I had a solution that contained two projects, one for the web layer that also contained the models, and another for a Windows forms project that did some other "stuff". The forms project referenced the web project, and all was fine up until I needed to reference something from the web project in the forms project, which I could not do for circular reference reasons.
So I created a new solution, put the data layer in one project and the web layer in another, so later on I could add the third project, and put in the references I need. Now when I run the web project, I get the following error;
So I understand that the web project is struggling to find my namespace from the data project, but I have referenced it, so I don't know what more to do.
***EDIT
This comes as no shock, but it's the view that's the issue. If I edit my Index.cshtml, it recognises the referenced project. I tried adding;
#using LottoData.Models
and intellisense completed as I typed. However, when I run it now, I get;
Help!
This was my bad. I forgot to change the output type for the data project to "Class Library", it was still set to "Console Program". Changed that, removed and re-added the reference, cleaned and rebuilt and it works fine now. Thanks #David and #Armand for your input.
I am adding one dll reference to my project. Whenever I modify the dll, I copy the dll the same folder overwriting the old one. But my compiler starts giving errors on the dll methods. Every time I have to remove the dll reference from the project and re-add the reference to build it.
My question is, why I need to remove and add reference every time? .NET should take the new dll automatically?
As others have stated, this appears to be a versioning issue. An alternative to adding the project to your solution (if you don't want it in there for some reason, or you have a requirement to reference the dll directly) is to modify your reference so that it doesn't look for a specific version.
Find the reference to the built assembly in the 'References' project folder
Right click on the reference
Change 'Specific Version' to false
hth
If you have one project depending on the other, put them in the same solution and add the dependant project as a "Project Reference" rather than referencing the DLL directly.
Alternatively, if you want to use an assembly in multiple places, you can create a NuGet package. You can place these in either public or private feeds - and then add the dependency using NuGet.
If you do either of these the dependency will be managed for you.
I know the error message is common and there are plenty of questions on SO about this error, but no solutions have helped me so far, so I decided to ask the question. Difference to most of similar questions is me using App_Code directory.
Error message:
CS0012: The type 'Project.Rights.OperationsProvider' is defined in an
assembly that is not referenced. You must add a reference to assembly
'Project.Rights, version=1.0.0.0, Culture=neutral, PublicKeyToken=null'.
Source File:
c:\inetpub\wwwroot\Test\Website\App_Code\Company\Project\BusinessLogic\Manager.cs
Following suggestions here and here, I have deleted all instances of Project.Rights.dll inside C:\Windows\Microsoft.NET/*.*
According to this, I checked if .cs files in question have build action set to "Compile". They do.
I have also double checked that the .cs file containing the "Project.Rights.OperationsProvider" type is deployed to App_Code directory.
For some reason, application is not looking for the type in the App_Code directory. Since I've deleted all instances of Project.Rights.dll (that I know of), I don't know which assembly the error message is mentioning.
When you get this error it isn't always obvious what is going on, but as the error says - you are missing a reference. Take the following line of code as an example:
MyObjectType a = new MyObjectType("parameter");
It looks simple enough and you probably have referenced "MyObjectType" correctly. But lets say one of the overloads for the "MyObjectType" constructor takes a type that you don't have referenced. For example there is an overload defined as:
public MyObjectType(TypeFromOtherAssembly parameter) {
// ... normal constructor code ...
}
That is at least one case where you will get this error. So, look for this type of pattern where you have referenced the type but not all the types of the properties or method parameters that are possible for functions being called on that type.
Hopefully this at least gets you going in the right direction!
Check target framework in the projects.
In my case "You must add a reference to assembly" actually meant, that caller and reference projects didn't have the same target framework. The caller project had .Net 4.5 , but referenced library had target 4.6.1.
I am sure, that MS compiler can be smarter and log more meaningful error message. I've added a suggestion to https://github.com/dotnet/roslyn/issues/14756
In my case this was because doing a NuGet package update had only updated references to a dll dependency in some but not all projects in my solution - resulting in conflicting versions. Using a grep-style tool to search text within *.csproj files in my solution it was then easy to see the projects that still needed to be updated.
When you get this error, it means that code you are using makes a reference to a type that is in an assembly, but the assembly is not part of your project so it can't use it.
Deleting Project.Rights.dll is the opposite of what you want. You need to make sure your project can reference the assembly. So it must either be placed in the Global Assembly Cache or your web application's ~/Bin directory.
Edit-If you don't want to use the assembly, then deleting it is not the proper solution either. Instead, you must remove all references to it in your code. Since the assembly isn't directly needed by code you've written, but instead by something else you're referencing, you'll have to replace that referenced assembly with something that doesn't have Project.Rights.dll as a dependency.
In my case, I was referencing a library that was being built to the wrong Platform/Configuration (I had just created the referenced library).
Furthermore, I was unable to fix the problem in Visual Studio Configuration Manager -- unable to switch and create new Platforms and Configurations for this library. I fixed it by correcting the entries in the ProjectConfigurationPlatforms section of the .sln file for that project. All its permutations were set to Debug|Any CPU (I'm not sure how I did that). I overwrote the entries for the broken project with the ones for a working project and changed the GUID for each entry.
Entries for functioning project
{9E93345C-7A51-4E9A-ACB0-DAAB8F1A1267}.Release|x64.ActiveCfg = Release|x64
{9E93345C-7A51-4E9A-ACB0-DAAB8F1A1267}.Release|x64.Build.0 = Release|x64
Entries for corrupted project
{94562215-903C-47F3-BF64-8B90EF43FD27}.Release|x64.ActiveCfg = Debug|Any CPU
{94562215-903C-47F3-BF64-8B90EF43FD27}.Release|x64.Build.0 = Debug|Any CPU
Corrupted entries now fixed
{94562215-903C-47F3-BF64-8B90EF43FD27}.Release|x64.ActiveCfg = Release|x64
{94562215-903C-47F3-BF64-8B90EF43FD27}.Release|x64.Build.0 = Release|x64
I hope this helps someone.
It just happened to me that different projects were referencing different copies of the same dll.
I made sure all referenced the same file on disk, and the error disappeared as I expected.
Unloading and reloading the class library in Visual Studio solved this for me.
For me, this was caused by the project both directly and indirectly (through another dependency) referencing two different builds of Bouncy Castle that had different assembly names. One of the Bouncy Castle builds was the NuGet package, the other one was a debug build of the source downloaded from GitHub. Both were nominally version 1.8.1, but the project settings of the GitHub code set the assembly name to BouncyCastle whereas the NuGet package had the assembly name BouncyCastle.Crypto. Changing the project settings, thus aligning the assembly names, fixed the problem.
It didn't work for me when I've tried to add the reference from the .NET Assemblies tab.
It worked, though, when I've added the reference with BROWSE to C:\Windows\Microsoft.NET\Framework\v4.0.30319
I had this issue on a newly created solution that used existing projects. For some reason, one project could not "see" one other project, even though it had the same reference as every other project, and the referenced project was also building. I suspect that it was failing to detect something having to do with multiple target frameworks, because it was building in one framework but not the other.
Cleaning and rebuilding didn't work, and restarting VS didn't work.
What ended up working was opening a "Developer Command Prompt for VS 2019" and then issuing a msbuild MySolution.sln command. This completed successfully, and afterwards VS started building successfully also.
one of main reason can be the property of DLL
you must before do any thing to check the specific version property if it true make it false
Reason:
maybe the source code joined with other (old)version when you build it , but this Library upgraded with new update the version now different in the Assembly Cash and your application forbidden to get new DLL ,and after disable specific version property your applacaten will be free to get the new version of DLL references
Maybe a library (DLL file) you are using requires another library. In my case, I referenced a library that contained a database entity model - but I forgot to reference the entity framework library.
This can also mean you use a library, which exposes (public) types that are defined in a library. Even when you do not use these specifically in your library (the one that doesn't build).
What this probably prevents is you writing code that uses a class (which in its signature has the types from a library not referenced) that you cannot use.
For me the reason why the error appeared was that the WebForm where the error was reported has been moved from another folder, but the name of its codefile class remained unchanged and didn't correspond to the actual path.
Initial state:
Original file path: /Folder1/Subfolder1/MyWebForm.aspx.cs
Original codefile class name: Folder1_Subfolder1_MyWebForm
After the file was moved:
File path: /Folder1/MyWebForm.aspx.cs
Codefile class name (unchanged, with the error shown): Folder1_Subfolder1_MyWebForm
The solution:
Rename your codefile class Folder1_Subfolder1_MyWebForm
to one corresponding with the new path: Folder1_MyWebForm
All at once - problem solved, no errors reporting..
The type 'Domain.tblUser' is defined in an assembly that is not
referenced. You must add a reference to assembly 'Domain,
Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'.
**Solved:**
Add reference of my domain library layer to my web app libary layer
Note: Make sure your references are correct according to you DI container
In my case this was because I used
Implicit Operator
between BLL and DAL classes.when I want to use BLL Layer In Application Layer I got this error.
I changed
implicit operator
to
explicit operator
it be OK.
Thanks
In my case the version of the dll referenced was actually newer than the one that I had before.
I just needed to roll back to the previous release and that fixed it.
I have a similar problem, and I remove the RuntimeFrameworkVersion, and the problem was fixed.
Try to remove 1.1.1 or
My problem was that the Output Type for one of my projects was set to Console Application. To fix this, I right-clicked the project, chose Properties, clicked the Application tab, and change Output Type (from Console Application) to Class Library. After I re-compiled, this error went away.
Clean your solution and rebuild worked for me (in Visual Studio, these are options you get when you right click in your solution explorer), the error is gone in my project.
so I need to add the Newtonsoft.Json.dll to the references of my Orchard project.(from http://www.youtube.com/watch?v=6MRzbJBvM7c)
So I use Nuget http://www.nuget.org/packages/NewtonSoft.Json/ which installs it to the Orchard.Web project. I then add the reference to my own project and select browse/Orchard.Web/bin and select Newtonsoft.Json
I then build the project and everything seems to work fine, later on when I build I get errors about Newtsonsoft.Json does not exist, i check the list of references in my own project and there is a yellow and black explanation mark beside it which says it is not available or does not exist.....
I thought it was something I done, so went back through the process and it worked fine, then later on the same thing happened....does anyone have any idea why?
Orchard does not place all of its assemblies in the bin because of the dynamic compile nature of Modules. These assemblies are created at runtime and placed into App_Data\Dependencies. Because of this single location, everything must be on the same version of the assembly or you may end up with Binding conflicts. Which gets us to the next part...
Orchard does not use NuGet. Instead, all of its references come from the lib folder to help ensure that everything is on the same assembly version of a dependent assembly. Newtonsoft.Json already exists within Orchard, and can be found within lib. Reference the assembly from /lib/newtonsoft.json/newtonsoft.json.dll in your Module, and everything should be working again.
I'm working on an MVC 3 project. I was told to get all the models and viewmodels out of the projects and put them in a class library so that they can be referenced from different types of projects. However, now that I've transferred all the viewmodels and models from the web project to a class library, and removed all the references to the web project, I cannot set reference to the class library from my web project with the reason stated in the question title. WHy is this happening? In my class library I'm not referencing the main project anywhere!!! Any suggestions? Thanks a lot!!
Experienced this earlier. Check the project that you are going to add if it has the reference to the project you are adding in it.
Example: Project A with reference to Project B. Then in Project B, you're adding Project A as reference.
well this usually happens for a reason, and this is that there is a cirrular reference,maybe not a direct one but an indirect one (through third project, how many projects do you have in your solution?).
In your library project remove all other projects references from solution, and try it again.
good luck
almir