Develop Reference

Missing an assembly reference

In a solution I am working on, in a sub project I have added a reference to another project. After adding the reference, I was able to successfully add the using statement and have the auto-complete pick up the right extension I was looking for. The code wrote as usual, but when I compiled, I get the error
The type of namespace name 'Name1' does not exist in the namespace 'Name2' (are you missing an assembly reference?)
So I have searched the forums, I have added several other system references and I have gotten nothing. I ran NuGet to update the solution packages, and that didn't make a difference either. For some reason, when I add the reference (using the add reference pop-up GUI) the reference to Name1 doesn't have a dll file in it. If I browse to the dll file directly, it still gives me the same issue when compiling.

Maybe you can copy the dll to [projectname] / Debug /
or [projectname] / Release /

The type or namespace name 'BussinessLib' could not be found (are you missing a using directive or an assembly reference?)

I have a web ASP.NET project with the bellow structure:
I copied this solution to my test computer and now I get
The type or namespace name 'BussinessLib' could not be found
HousingSurvey is the startup project .
Each project get built successfuly but when I try to build the solution I get
The type or namespace name 'BussinessLib' could not be found
As you see BussinessLib is a reference for Housingsurvey. The using BussinessLib statement is set correctly in the HousingSurvey .
So I rebuild BussinessLib and add the reference to Housingsurvey. Housing Survey as a project builds successfully. but again when I build the solution I get The type or namespace name 'BussinessLib' could not be found
To make things stranger when I check
C:\CSharpTest\HousingSurvey\HousingSurvey\BussinessLib\bin\Debug
BussinessLib.dll is deleted somehow(After I build the solution). I double checked BussinessLib.dll and saw it does get created there whenever I build the BussinessLib project.
I found the most promising answer here:
The type or namespace name could not be found
But above answer did not help me since all of 3 projects in my solution are targeted to the .NET Framework 4.5
Any feedback is greatly appreciated.
Update: please note that this whole solution builds "Successfully" in my UAT computer. Then I copy paste it to the test computer and it fails on build.
For some weird reason, whenever I build the whole solution, Business.dll gets deleted from the bin folder! and that's why code that references it can not find it.

From the HousingSurvey Project, delete the reference to BusinessLib and re-add it again. It is probably an issue with a file path for the original reference.
Also when you add the reference to the project again, be sure to set the 'Copy Local' property to True
In Solution Explorer, click the Show All Files button to display the References node.
Open the References node for the project.
Right-click a reference in the References list, and click
Properties. The properties associated with that reference appear in
a list in the Properties window.
Select Copy Local from the
left-hand column, and then click the arrow in the right-hand column
to change the value to True or False.

"Assembly Same Simple Name already been imported" error

This is a CLR project. I'm importing two DLL files with the same name, quizz.dll (I rename the old version as legacyquizz.dll) and I include the newer version as quizz.dll into a legacy converter test project. (The legacy converter project being tested only imports the old quizz.dll).
This is the error I'm getting . . .
An assembly with the same simple name 'Quizz,
Version=2.0.0.1, Culture=neutral,
PublicKeyToken=null has already been imported.
Try removing one of the references or sign them to
enable side-by-side. c:\ . . . \Quizz.dll
The path it's pointing to is the destination of the newer version of quizz.dll.
I'm using an external alias on the legacyquizz.dll file:
extern alias legacy;
What is a "simple name" in this context?

You can see the simple name by opening project properties and selecting Assembly Information:
To sign the assembly you need to select Signing tab and create or select signing key:

You have two assemblies with the same name (not file name, assembly name). There are two solutions to this:
Rename one of the assemblies from the project's properties and recompile.
Set up Strong-Name Signing on the assembly to allow two separate versions of the same assembly to coexist.

If you are working with the new .csproj version, you may encounter this problem after you add a reference to another solution project, if the reference already exists as an Assembly Dependency (this reference may have been added automatically by Visual Studio).
On Solution Explorer, expand the conflicting project, navigate to Dependencies->Assemblies and check that there is not an existing reference to the assembly that is raising the conflict. If it exists, just delete it and the conflict will be resolved.

I too seems this problem in my project. I had changed my dll path to another folder, and changed the reference path too for the same(dependency Layers). It will work. No duplication occurs.

microsoft.visualbasic.fileio does not exist

I am on .NET Framework 4.0, building a C# web application in VisualStudio 2012. I have Microsoft.VisualBasic added as a reference to the project. I am having trouble with the following line of code:
using Microsoft.VisualBasic.FileIO;
Building the solution returns the error: The type or namespace name 'FileIO' does not exist in the namespace 'Microsoft.VisualBasic' (are you missing an assembly reference?)
I have removed and re-added the reference to the assembly Microsoft.VisualBasic, but still get the error. Microsoft.VisualBasic is in the GAC, as well as Microsoft.VisualBasic.Compatibility, Microsoft.VisualBasic.Compatibility, Microsoft.VisualBasic.PowerPacks.Vs, and Microsoft.VisualBasic.Vsa.
Please let me know how to get VS2012 to recognize the FileIO namespace.

Right-click on your project and select Add Reference...
In the Reference Manager, expand Assemblies and select Framework. Then check the box for Microsoft.VisualBasic and click OK.

I had similar issue, fixed by change TargetFramework (in .csproj) from netstandard2.0 to netcoreapp3.0.

Application references are not available to uncompiled files in your application (aspx, ashx). There are two solutions to this issue as follows:
1) Move your code to a compiled part of the application (cs/vb file)
or
2) Add the reference to the web config
My reference was in an ashx file. I simply copied the code from the ashx file to the clipboard, deleted the file from the project, added a new Generic Handler (right click in Visual Studio > Add > Generic Handler), entered the same name as before, and pasted the code from the clipboard into the cs file editor that Visual Studio opened. I now have a cs file that will compile with the project and use the project reference. The file name is the same, so there is no need to update anything else -- just rebuild and deploy.

Webservice reference cannot find assembly reference

I have a c# project with a reference that cannot be found when checking in to TFS. The project runs fine when i debug.
It its in my services project the problem is located. I have a reference to lets say ProjectSec. And i have a wewbservice reference to Projectservice.
The webservice uses the ProjectSecurity.Security namespace that is located in the ProcectSec assembly.
When i check in my files i get the following error:
The type or namespace name 'ProjectSecurity' could not be found (are you missing a using directive or an assembly reference?)
Could not resolve this reference. Could not locate the assembly "ProjectSec". Check to make sure the assembly exists on disk. If this reference is required by your code, you may get compilation errors.
The ProjectSec.dll is located in the lib folder and its there. There is no error when i try to use it elsewhere in my project.
This may not be a perfect explanation but does anyone know what i could try?
I have removed the reference and added it over again, but no luck.

A common pitfall with TFS-build is to have in Source Control something, for example, like this:
$/Sources/Webservice
$/Libs/ProjectSecurity
And then, in the build definition that is validating your checkin, to have only
Active | $/Sources/Webservice | $(SourceDir)
as workspace mappings.(You can access this by right-clicking on the build definition in TeamExplorer, select "Edit Build Definition.." & go to Tab "Workspace")