Develop Reference

SpecFlow .feature.cs file gets duplicated when feature file is edited

When I edit Foo.feature, SpecFlow creates a new Foo1.feature.cs instead of overwriting Foo.feature.cs. The duplicated file then causes compile errors due to duplicated symbols.
It happens only for one of the .feature files in my project - all others behave normally. All the .feature and .feature.cs files are under source control and added to the Foo.csproj file.

I think I found the problem - in my .csproj file I had this entry:
<None Include="Foo.feature">
<Generator>SpecFlowSingleFileGenerator</Generator>
<LastGenOutput>Foo1.feature.cs</LastGenOutput>
</None>
I think the <LastGenOutput> was confusing SpecFlow. I don't know where it came from, but changing it to <LastGenOutput>Foo.feature.cs</LastGenOutput> fixed the issue.
Edit: I just found out that a missing <LastGenOutput> tag can also cause a duplicate Foo1.feature.cs file to be created. So if the tag is missing create it and put the correct filename in it.
After googling for SpecFlow and "LastGenOutput", I found this thread - https://groups.google.com/forum/#!topic/specflow/SpOihmvoAOQ. It outlines the same problem and solution:
Issue may be very annoying. Possible solution (do at you own risk!)
delete all YourFeature1.feature.cs files in Visual Studio. Save project.
close Visual Studio, open your .csproj file with notepad
find the lines similar to this one:
YourFeature1.feature.cs
change them to
YourFeature.feature.cs
save, load project in Visual Studio. Enjoy.
But you have to already know the solution in order to find that thread.

Source file in CSC cannot be found

After a struggle with creating a database (first with an entity framework, after without), we have a database (and an EntityModel_HFFContext file we don't use, it's not connected). Normal work proceeded, and I installed a NuGet-package for an MVC sitemap.
From that moment, the project worked fine, but after a couple of days two warnings came up about two files missing: "The parent file, 'EntityModel_HFF.tt', for file 'locatie.cs' cannot be found in the project file." ("HFF" is the project name in here) and then those multiplied themselves into errors: "Source file 'locatie.cs' cannot be found" in a CSC file I cannot find.
These two files ('locatie.cs' and 'klant.cs') are not in any view, but somehow they are displayed outside all folders, saying they do not excist (see this screencapture). I have tried to delete those files manually, but that did not have any success. I have tried some other ways too, but that resulted into the complete deletion of the database, so now I am somewhat desperate.
I have no idea where to look and what to do, to get rid of these two files (or probably references to these files, since we don't use them at all), so I don't have these errors anymore. Has anyone of you have a clue of where I need to look (e.g. where this CSC file is) and what I need to adjust to fix this?
Maybe it can be useful to know I use Visual Studio 2013.
Update
I fixed the errors by unloading the project, editing the .csproj file and commenting out
<Compile Include="klant.cs">
<DependentUpon>EntityModel_HFF.tt</DependentUpon>
</Compile>
(and the other one too). Now these errors are gone - is this a safe way to do this?

The reason why you get the error is because when you deleted the locatie.cs and klant.cs file, you didn't remove them from the project solution itself, therefore, Visual Studio is expecting the file to be part of the project but is unable to find them, which explains the yellow warning signs.
Like what you said, all you have to do is to remove the files from the solution as they no longer exists. So yes, it is safe to comment out that portion in the .csproj file.
Although, I would like to mention that you didn't have to go to that much trouble, all you had to do was to delete the file in your solution in Visual Studio, since they no longer exists anyway.

Error : Two output file names resolved to the same output path: "obj\Debug\Project1.Form1.resources"

I'm getting the error:
Two output file names resolved to the same output path: "obj\Debug\Project1.Form1.resources"
This error comes while trying to run a windows form application I created. Some searches showed me that this occurs due to the occurrence of two .resx files. I have two .resx files in my application. Also I have two forms in my application. I created the second form by copying the first form and renaming and modifying the copy. The two .resx files are form1.resx and form2.resx. How can I remove this error?

Though I don't know why will you do it, you can use these instructions to copy properly a form. It is not recommended. It is better to inherit or use user control. But if you must:
Delete the second form.
Recreate it by actually creating a form
Copy the InitializeComponent method from form1.designer to the new form
Also copy the part below InitializeComponent.
Copy the code of form1 to the new form, make sure to fix the constructor
Please do not copy a full form using copy paste
EDIT
When someone pushes the change page button you can do:
private void button1_Click(object sender, EventArgs e)
{
Form2 frm = new Form2(NextPage);
frm.Show();
this.Hide();
}
Now this is very basic syntax. you might want to have a master form that holds all the forms so you won't create over and over new forms.
The design is up to you. this example will give you basics on how to open and close forms.

If you don't need the resx files you can just delete them and this problem goes away.

This error may also occur if you use Windows10 and you have localiztion resources for CR-Cyrl-CS, CR-Latn-CS cultures. Windows10 doesn't support them any more.

I encountered this problem while making a form application. When I changed the form name, the compilation problem arose due to the same error. In Visual Studio, I saw that a .resx file with 2 different names was created in the sub-tabs of the form that I changed its name in the Solution Explorer section. I deleted oldname.resx and it was fixed.

In my case, it was not showing me 2 copies of .resx files. I simply restarted Visual Studio 2010 and the problem disappeared.

I added twice a second form called FormSettings to my project and later I was getting the described error.
In order to fix it, I removed FormSettings from the project. After that, I renamed all the files whose name was FormSettings to FormSettingsOld. When I built the application, it was giving errors about FormSettings.
I performed a search for all files in the project which contained a reference to FormSettings. I found that ProjectName.csproj was making reference to FormSettings and I deleted the duplicate XML entris related to FormSettings, such as
<Compile Include="FormSettings.Designer.cs">
<DependentUpon>FormSettings.cs</DependentUpon>
</Compile>
<Compile Include="FormSettings.Designer.cs">
<DependentUpon>FormSettings.cs</DependentUpon>
</Compile>

When copying a form it seems that the class name of the source form is being renamed to the name of the new form, at least if you rename the new form. I restored the original name of the destination form (class file, constructor and designer file). Remember also to go through any usage of the original class name as changes also are need here. That solved the problem.
(Visual Studio 2010)

How to fix "namespace x already contains a definition for x" error? Happened after converting to VS2010

Specifically the error occurs in the Resources.Designer.cs:
Error 2 The namespace 'ModulusFE' already contains a definition for 'StockChartX' Resources.Designer.cs 11 21 ModulusFE.StockChartX
I've googled this and am still quite confused. Does anyone know anything I might try?
I have tried rebuilding and cleaning, as well as renaming the Resources.Designer.cs file in hopes that it would rebuild, but no luck.
The top of the code says this:
// <auto-generated>
// This code was generated by a tool.
// Runtime Version:4.0.30319.225
//
// Changes to this file may cause incorrect behavior and will be lost if
// the code is regenerated.
// </auto-generated>
Any ideas whatsoever would be appreciated.

Looks like a bug in VS code's OmniSharp.
Solution for me was to execute command "Restart OmniSharp".
Just do:
- ctr shift P
- type "Restart OmniSharp" .. hit enter
This fixed it for me.

I had this happen to me about a year ago and I don't remember exactly what the root cause was, but there are two things you might try:
If it's an auto-generated file (as 'Resources.Designer.cs' tend to be), try deleting it and letting VS re-generate it.
Either separately or in conjunction with #1, select Show All Files in the Solution Explorer or open the solution folder in Windows Explorer - it could be that a version of the file somehow got excluded from the project and is therefor 'invisible' to VS but still makes it angry...

I've had this problem, too, and it was because I created a new namespace, but the parent namespace contained a class with the same name.

This is an old question but I didn't find the fix I used, so I've added it here.
In my case it was a namespace with the same name as a class in the parent namespace.
To find this, I used the object browser and searched for the name of the item that was already defined.
If it won't let you do this while you still have the error then temporarily change the name of the item it is complaining about and then find the offending item.

Unfortunately, none of the other answers helped.
My problem specifically occurred in a WPF project.
The problem arose when I created a folder under the MainWindow folder, which effectively created a namespace something like ProjectName.MainWindow.Folder.
Now, I believe because of some static designer code, Visual studio gets confused between the class MainWindow and the namespace Project.MainWindow.Folder .
As a solution, I moved the Folder out of MainWindow. Looking at the Class View or the solution/project helps to recognize what namespaces and classes within them exist.

This just happened to me. What happened was that I duplicated a project that was originally under source control. Although I properly renamed everything, the file permissions on all the files were still set to read-only. When I started modifying some form controls, Visual Studio automatically created a Resource1 file because the original Resource file was read-only.
What I did to fix this was as follows:
allow write permissions on the project files.
deleted the original Resource file
Ctrl-A for all form elements, then Ctrl-X to cut them.
Save the form.
Ctrl-V to paste them all back.
Save the form.
I had to do this because the auto-generated code wasn't updating on it's own, so I "forced" it to update by making a change to the form. Not doing this left a bunch of code from form elements that no longer existed prior to changing the file permissions.

I had an xaml file with the following definition
<Window x:Class="mm2.Views"
.etc..
/>
mm2.Views was the name of a namespace in my app.
To fix it, I correctly renamed the xaml object:
<Window x:Class="mm2.Views.RecordedTracks"
.etc..
/>

I had a similar problem and resolved it by removing any copies/backups of the .cs file from the directory.

I had this same problem and it was due to naming a function in the code behind the same as my tool. Simple mistake but something to keep in mind as well.

I had a similar issue however found a different solution than what I have read. I came to my fix after reading P Walker's answer.
My issue happened when I named my resource file for Japanese language incorrectly. Long story short I was trying to create a Resource for Japanese but I accidentally named it localized.jp.resx. I then realized that the iso language code is ja not jp for Japanese. Once I changed the file name to localized.ja.resx and deleted everything that was in the designer file it fixed my problem.
This is what fixed my problem hopefully it helps someone else.

I came across a similar problem. After generating my database from an edmx file, I clicked 'save all' and 'build' and all the Types/Model classes that I created showed up in the error box. I researched why this happened and like your replies suggest, I thought it was something that was auto-generated.
However, solutions like deleting the auto-generated classes and re-generating them didn't work for me.
I eventually ran out of patience and decided I'd fix it another way. Since my script was saved, I just deleted the edmx file (and its reference in the web.config) and went back and created another one using "model from database" and didn't touch it after that.
Needless to say, I was pretty mad that it turned out like that.

Me too got this error,
When I change my WPF project's Target Framework to Framework Version 4.0 Client Profile -> Framework 4.0. It's solved by itself.

The way I solved it was to remove all of the enums from the model browser, and then re-add them again. Somehow miraculously the tool regenerated everything perfectly and the error message went away (I'm using VS2012, FYI).

What helped me many times, was just turning it off and on again..
Ctrp + shift + P -> Reload window in VS Code
Close and open the project/window.
Cleaning all bin, obj contents (in power shell)
Get-ChildItem .\ -include bin,obj -Recurse | foreach ($_) { remove-item $_.fullname -Force -Recurse }
After this, it can be that I am missing something else, like some package reference or include, but usually it is, that underlying parser/compiler (omnisharp) just gets messed up and needs some restart to work properly again.

This may be a bit of an edge case, but we've run across this in our development environment from time to time. We had to setup a custom culture in Windows to support en-HK. Windows 8.1 now supports this culture natively as does Windows 2012 R2, but older machines need to have the culture created. Any machine that does not have this culture setup will get this error reported. The solution is to create the culture on the machine (We have a console app created for this purpose) and everything starts working again.

I had the same issue just now, and I found it to be one of the simplest of oversights. I was building classes, copying and pasting code from one class file to the others. When I changed the name of the class in, say Class2, for example, there was a dropdown next to the class name asking if I wanted to change all references to Class2, which, when I selected 'yes', it in turn changed Class1's name to Class2.
Like I said, this is a very simple oversight that had me scratching my head for a short while, but double check your other files, especially the source file you copied from to ensure that VS didn't change the name on you, behind the scenes.

If you are using different aspx.cs files that define classes of the same name you can use
<compilation targetFramework="4.5" />
under <system.web> in your web.config file.
Although I would still strongly advise that you would change the class name.

This is not the best solve, but if you really don't care it is an easy solution.
I simply renamed my class. So I had class Card and I changed it to MyCard.

I think this issue is because you have added for a single table, 2 DAL classes.
If this table is included in a relation, then remove the table_name.dbml for it, and keep that for the related tables.
You must use one of them.

I had a similar problem (Universal project, Visual Studio 2015), I solved it with the following changes:
In App.xml.cs was (it was ok):
namespace Test.Main {
Wrong, old version of App.xml:
x:Class="Test.Main"
Good, new version of App.xml:
x:Class="Test.Main.App"

I had something similar to this happen in my WPF application. It arose when I was trying to do some cleanup by declaring a namespace that was more descriptive. The problem arose because I had named the namespace in the code-behind (or cs) the same as the Window class. The namespace in the code-behind should have the last section stripped (after the rightmost dot) and used to declare the class and instantiate it. Notice Win below:
xaml
<Window x:Class="FrameApp.UI.Invoice.Win" ...>
code-behind
namespace FrameApp.UI.Invoice
{
public partial class Win : Window
{
public Win()
}
}
An obvious oversight but it set me back at least an hour with all the errors that appeared.

I had this issue, but mine was slightly different to the issues mentioned here. I was cleaning up my project and moving around some classes into new folders. I had a 'AddFilter' class that I moved into an 'AddFilter' folder - so I had actually wound up with a class that was sharing the name of a namespace. This was a bit tricky to spot at first because I couldn't find any other classes that it was conflicting with; it was conflicting with the namespace instead.

If you copy&paste your pages don't forget to rename class names. Otherwise you get this error also with "Type already defines a member called 'OnGet' with the same parameter types"

look this happend to me when I created new file inside a folder with the same name of class in the project { folder name : Folder } and there is class name { Folder } so the namespace was the namespace.Folder so that the compiler assume that the cass defined in two places
in new file :
namespace APP.Folder
{
partial class NewFile
{
// ....
}
}
in the other file (the file that hase the problem):
namespace APP
{
partial class Folder
{
// ....
}
}
-- so you can edit the folder name or remove the .Folder from the namespace at the new file

I know this is an older post, but I thought it might help someone else if I shared my experience with this error. For me, I was working in Visual Studio 2019 and using Xamarin Forms. I received this error message when I created a new folder and named it the same as a Content Page I had made previously. Apparently we're not supposed to do that...
Anyways, I had to rename the folder then go through to each individual Content Page within the folder are change their namespace (in their .cs file) as well as the x:Class within their ContentPage tag (in their .xaml file) to reflect the folder's new name.
That's what worked for me. I hope it is helpful to someone else in the future should the error rise again.

I've had this problem recently, all i did is rename the file and class then build. then return again the original filename. It worked.

This happened to me, I noticed that there was actually another class with that same name under the same namespace "OtpService.Models.Request", so all I did was to just change the namespace of the 2nd class to "OtpService.Models.Request.ExtraObj". I did this because I did not want to change the name of the conflicting class to anything else.

I came across this partial class problem in a winform of a solution after converting from .net 4.5.1 to 4.7.2.
Initially the problem the compiler was not complaining about partial class but the use of properties.default...without qualification. After adding Global::solnNameSpace. qualifiers, then I got the partial class problem.
after viewing answers in this thread, I look at the resource designer file, I found it was generated with explicit solnNameSpace while the classes in the solution did not. Also the solnNameSpace is the same as the name of the problematic class name.
To fix the problem with the least effort and time I backed out Global... qualifier and removed the explicit namespace ... and end statements from the resource designer file. I know I may get in trouble later on if there were changes that cause auto generation of the resource designer file but I was was under tight deadline. I made documentation on the temp change instead of a better long term solution since the solution is under no change allowed for nature of the solution and multi project use.

I had this problem. It was due to me renaming a folder in the App_Code directory and releasing to my iis site folder. The original named folder was still present in my target directory - hence duplicate - (I don't do a full delete of target before copying) Anyway removing the old folder fixed this.

when you have tried everything else and still get the same trouble, there is a way out; however it will be tedious and need careful preparation.
Start another new project using existing files, or edit the project .csproj file if you are proficient in editing csproj (need backup). I will list steps for new project.
preparation:
note all references and their sources
note all included files from another project
rename the orginal projectname.csproj file
close solution/project
start new project using existing files(you will get errors from references)
add back the noted references
include/add existing file from other project(s)

What does MissingManifestResourceException mean and how to fix it?

The situation:
I have a class library, called RT.Servers, containing a few resources (of type byte[], but I don't think that's important)
The same class library contains a method which returns one of those resources
I have a simple program (with a reference to that library) that only calls that single method
I get a MissingManifestResourceException with the following message:
Could not find any resources
appropriate for the specified culture
or the neutral culture. Make sure
"Servers.Resources.resources" was
correctly embedded or linked into
assembly "RT.Servers" at compile time,
or that all the satellite assemblies
required are loadable and fully
signed.
I have never played around with cultures, or with assembly signing, so I don't know what's going on here. Also, this works in another project which uses the same library. Any ideas?

All I needed to do to fix this problem was to right-click the Resources.resx file in the Solution Explorer and click Run Custom Tool. This re-generates the auto-generated Resources.Designer.cs file.
If the .resx file was added to the project manually, the Custom Tool property of the file must be set to "ResXFileCodeGenerator".
The problem is due to a mismatch of namespaces, which occurs if you change the "default namespace" of the assembly in the project settings. (I changed it from (previously) "Servers" to (now) "RT.Servers".)
In the auto-generated code in Resources.Designer.cs, there is the following code:
internal static global::System.Resources.ResourceManager ResourceManager {
get {
if (object.ReferenceEquals(resourceMan, null)) {
global::System.Resources.ResourceManager temp = new global::System.Resources.ResourceManager("Servers.Resources", typeof(Resources).Assembly);
resourceMan = temp;
}
return resourceMan;
}
}
The literal string "Servers.Resources" had to be changed to "RT.Servers.Resources". I did this manually, but running the custom tool would have equally well done it.

I just came across this problem today, and I found this Microsoft Help and Support page that actually did work around the problem.
I had a couple delegates at the top of my file, in the global namespace, and all of a sudden I was getting a MissingManifestResourceException when running the program, on this line:
this.Icon = ((System.Drawing.Icon)(resources.GetObject("$this.Icon")));
Then I moved the delegates into the namespace, got the same error. Finally I put the delegates in the only class in that file, and the error went away, but I didn't want the delegates in that class or namespace.
Then I came across that link above, which said
To resolve this problem, move all of the other class definitions so that they appear after the form's class definition.
I put the delegates (which I would not consider "class definitions") at the bottom of that file, outside of the local namespace, and the program didn't get the MissingManifestResourceException anymore. What an irritating error. But, that seems like a more robust solution than modifying the auto-generated code :)

I've run into a similar issue and, although I know it isn't the cause the OP had, I'll post it here so that if someone else runs across this problem in the future, an answer will be available.
If you add a class before the designer class you will get a MissingManifestResourceException exception at runtime (no compile time error or warning) because
Visual Studio requires that designers use the first class in the file.
For (slightly) more information see this post.

I had the same problem, but using the Run Custom Tool command as suggested by Timwi did not help in my case.
However it lead me into the right direction, because I ended up in the Properties of the .resx file. Here I noticed a difference to another .resx file that caused no problems.
In my case I had to change the property "Build Action" from "Resource" to "Embedded Resource".
My best guess for the reason is, that I had the .resx in a library that was used from another application. My application did not have its own .resx file, so it had to use the one from the library - which is only available when it's embedded in the library and not "stand alone".

When I run in a similar issue, in Vs 2012, it turned out that the "Custom Tool Namespace" property of the resx file was wrong (in my case, actually, it was unset, so the generated code yeld this exception at runtime).
My final set of properties for the resx file was something like this:
Build action: Embedded Resource
Copy to Output Directory: Do not copy
Custom Tool: ResXFileCodeGenerator
Custom Tool Namespace: My.Project.S.Proper.Namespace

I ran into a different cause of this problem, which was unrelated to resx files. I had a class library where AssemblyInfo.cs contained the following:
[assembly: ThemeInfo(
ResourceDictionaryLocation.SourceAssembly,
ResourceDictionaryLocation.SourceAssembly)]
The assembly did not contain any WPF code, theme or Resource dictionaries. I got rid of the exception by removing the ThemeInfo attribute.
I did not get an actual exception, only
A first chance exception of type 'System.Resources.MissingManifestResourceException'.
Viewing exception details, the system was requesting MyAssembly.g.resources
Hope this might be of help to someone else.

Also see: MissingManifestResourceException when running tests after building with MSBuild (.mresource has path in manifest)
I repeat the answer here just for completeness:
It appears adding LogicalName to the project file fixes it:
<LogicalName>$(RootNamespace).Properties.Resources.resources</LogicalName>
i.e. so the embedded resource entry in the project file looks like this:
<ItemGroup>
<EmbeddedResource Include="Properties\Resources.resx">
<Generator>ResXFileCodeGenerator</Generator>
<LastGenOutput>Resources.Designer.cs</LastGenOutput>
<LogicalName>$(RootNamespace).Properties.Resources.resources</LogicalName>
</EmbeddedResource>
</ItemGroup>
This is detailed in: http://blogs.msdn.com/b/msbuild/archive/2007/10/19/manifest-resource-names-changed-for-resources-files.aspx
Note that we are using a .resx file, but the bug still appears to occur.
Update: The problem with resources (incl. XAML) appears to be related to output paths and the use of forward or backward slashes as detailed in:
Why does modifying project output directories cause: IOException was unhandled "Cannot locate resource 'app.xaml'."

Not sure it will help people but this one worked for me :
So the issue I had was that I was getting the following message:
Could not find any resources appropriate for the specified culture or the neutral culture. Make sure "My.Resources.Resources.resources" was correctly embedded or linked into assembly "X" at compile time, or that all the satellite assemblies required are loadable and fully signed"
I was trying to get the resources that were embedded in my project from another class library.
What I did to fix the problem was to set the Access Modifier in the tab Project->Properties->Resources from "Internal" (accessible only within the same class library) to "Public" (accessible from another class library)
Then run and voilà, no more error for me...

The solution given by BlaM worked for me too.
I am a VS 2013 User. After going through many fixes but no luck, I tried this:
Right-click the resource file, one-by-one, in case of multiple-files.
Make sure, the property "Build Action" is set to "Embedded Resource".
That's it! :)

I had the same issue, but in my case i places a class in a usercontrol which is related to the usercontrol like this
Public Class MyUserControlObject
end Class
Public Class MyUserCOntrol
end Class
The solution was to move the MyUserControlObject to the end of the Usercontrol class, like this
Public Class MyUserCOntrol
end Class
Public Class MyUserControlObject
end Class
I hope this helps

I was getting the MissingManifestResourceException error after I ported my project from VS2005 to VS2010. I didn't have any other classes defined in the file that contains my Form class. And I also had my resx Resource File Name set correctly. Didn't work.
So I deleted the resx files and regenerated them. All good now.

Recently ran into the same problem, struggled for a bit, found this topic but no answers were correct for me.
My issue was that when I removed main window from my WPF project (it does not have a main window), I forgot to remove StartupUri from App.xaml. I guess this exception can happen if you have a mistake in StartupUri, so in case if anybody is struggling with this - check your StartupUri in App.xaml.

Recently stumbled upon this issue, in my case I did a few things:
Make sure the namespaces are consistent in the Designer.cs file of the resx file
Make sure the default namespace of the Assembly(right click the project and choose Properties) is set the same to the namespace the resources file is in.
Once I did step 2, the exception went away.

I had this problem when I added another class in the file just before the class which derived from Form. Adding it after fixed the problem.

Also the same error may occur when you put a new class into the source code of a designer created form's class.
This new class may be removed, and placed in a different cs file.
(At least in my case this was the problem...)

Because I am pre-compiling my web application (using VS2012 publish feature). I was getting the error above. I tried all the suggestions, but weirdly changing 'Build Action' to 'Content' did the trick!

In my case, I have a web api with resources and I create a nuget package from that. When I use this nuget in other projects, I realise that when I request a api with resources, I am getting MissingManifestResourceException after a bit reasearch, I learn nuget packager is not packing resources automatically. If you want to use resources files, you have to do that manually. So you need to add below lines to your .nuspec file:
(Visit https://github.com/NuGet/Home/issues/1482)
<package>
<metadata>
</metadata>
<files>
<file src="bin\Debug\en\MyAssembly.resource.dll" target="lib\net40\en\MyAssembly.resource.dll" />
<file src="bin\Debug\es\MyAssembly.resource.dll" target="lib\net40\es\MyAssembly.resource.dll" />
</files>
</package>
But, before adding files, you need to be sure which version of .net you are using.

I had the with a newly created F# project.
The solution was to uncheck "Use standard resource names" in the project properties -> Application -> Resources / Specify how application resources will be managed.
If you do not see the checkbox then update your Visual Studio! I have 15.6.7 installed. In 15.3.2 this checkbox is not there.

Just to mention. If you use a constant or literal, make sure it refers to a resource of the form ProjectName.Resources, and does not cpntain Resources.resx.
It could save you an hour or two .

I've encountered this issue with managed C++ project based on WinForms after renaming global namespace (not manually, but with Rename tool of VS2017).
The solution is simple, but isn't mentioned elsewhere.
You have to change RootNamespace entry in vcxproj-file to match the C++ namespace.

In my case it was a typo in the Xaml of a window opened from Winforms Form:
Incorrect: <Image Source="/Resources/WorkGreen.gif"/>
Correct: <Image Source="../Resources/WorkGreen.gif"/>
It may help someone

In my case I have changed my project namespace and hence my solution was throwing "missingmanifestresourceexception" exception. Instead of right clicking the .resx file in the solution explorer and clicking on "Run Custom Tool" option, I have replaced the
rootnamespace to new namespace in .csproj file(RootNamespace) and rebuilded the solution again. All Resources.Designer.cs files namespaces got automatically changed with new namespace.
I hope my answer will help someone.

If you're getting this while generating a C# project using CMake, the solution I found may help you.
Your CMakeLists.txt file needs
set_property(TARGET yourTargetName PROPERTY VS_GLOBAL_RootNamespace yourRootNamespace)
Substitute your own values for yourTargetName and yourRootNamespace, obviously.
Then the resources will get embedded in your assembly!

One more reason to get this error is- '.resx' file excluded from project.
In my case, '.resx' file was excluded from project.
Select 'show all files' option in solution explorer.
Right click on '.resx' file(s) and click include in project.
Rebuild the project/solution.

I read all the answers and nothing worked for me. Most likely my situation is different, but same error. My issue was that I had two projects. Second project had a lot of forms added to it from the first one as "Add as link".
For WinForms, there are 3 required files: the code, the designer, and the resource files. If you add all 3 files at the same time as "Add as link", Visual Studio does not link them together as same form. It will compile, and run, but it will blow up with the same MissingManifestResourceException error.
Fix: You have to do them individually, in order: code file --> designer file --> resource file. Then they are grouped and no more error, at least for me.

From the Microsoft support page:
This problem occurs if you use a localized resource that exists in a satellite assembly that you created by using a .resources file that has an inappropriate file name. This problem typically occurs if you manually create a satellite assembly.
To work around this problem, specify the file name of the .resources file when you run Resgen.exe. While you specify the file name of the .resources file, make sure that the file name starts with the namespace name of your application. For example, run the following command at the Microsoft Visual Studio .NET command prompt to create a .resources file that has the namespace name of your application at the beginning of the file name:
Resgen strings.CultureIdentifier.resx
MyApp.strings.CultureIdentifier.resources