Ошибка компилятора cs0234

We’re working on a WPF project using Visual Studio 2015. We’ve got a folder in the project named Assets. It shows up fine in VS 2015. The files in it show up fine in the Solution Explorer. But when we build it, VS 2015 complains with the following error:

Error CS0234 The type or namespace name ‘Assets’ does not exist in
the namespace ‘CoreFramework’ (are you missing an assembly
reference?)

(CoreFramework is the name of our solution and the project that Assets is in.)

I don’t get how the folder is there in CoreFramework, but when building it, VS 2015 just doesn’t see it. I’ve tried cleaning both the project and the solution in VS 2015, but it doesn’t help at all. The same errors keep popping up. And they popup in our nightly builds as well.

So what is causing VS 2015 to simultaneously see a folder within a project and not see that same folder in the project?

In this case what I had to do was to delete everything in the obj folder beneath our project main folder. The solution’s name is CoreFramework and the main project’s name is also CoreFramework. So what I did was go to \CoreFramework\CoreFramework\obj and deleted everything there. Since at this point we’re only dealing with a debug version, the only thing there was the Debug folder and all temporary files and folders under that. Once I did that, then rebuilding the solution re-created all of the temporary files and folders, without the problem I was having with the Assets folder. It built fine.

YMMV

answered Feb 16, 2016 at 18:47

Check the .Net-Framework Versions of both Projects. If the referenced project has a higher .Net-Framework Version than the referencing project this error might occur.

ProjectName -> Properties -> Application -> Target framework

answered Jun 25, 2021 at 12:44

I had the same issue after I manually copied the referenced DLL file.
I solved it by displaying the reference properties in the Solution explorer then changing the Specific version setting from True to False and finally changing it back to True.
I rebuild and… it works just fine. Do not ask me why…

Note : I had to do the same for each project which had the CS0234 error message

PS : in my case Visual studio version is 16.1.6

answered Dec 30, 2019 at 13:25

We’re working on a WPF project using Visual Studio 2015. We’ve got a folder in the project named Assets. It shows up fine in VS 2015. The files in it show up fine in the Solution Explorer. But when we build it, VS 2015 complains with the following error:

Error CS0234 The type or namespace name ‘Assets’ does not exist in
the namespace ‘CoreFramework’ (are you missing an assembly
reference?)

(CoreFramework is the name of our solution and the project that Assets is in.)

I don’t get how the folder is there in CoreFramework, but when building it, VS 2015 just doesn’t see it. I’ve tried cleaning both the project and the solution in VS 2015, but it doesn’t help at all. The same errors keep popping up. And they popup in our nightly builds as well.

So what is causing VS 2015 to simultaneously see a folder within a project and not see that same folder in the project?

In this case what I had to do was to delete everything in the obj folder beneath our project main folder. The solution’s name is CoreFramework and the main project’s name is also CoreFramework. So what I did was go to \CoreFramework\CoreFramework\obj and deleted everything there. Since at this point we’re only dealing with a debug version, the only thing there was the Debug folder and all temporary files and folders under that. Once I did that, then rebuilding the solution re-created all of the temporary files and folders, without the problem I was having with the Assets folder. It built fine.

YMMV

answered Feb 16, 2016 at 18:47

Check the .Net-Framework Versions of both Projects. If the referenced project has a higher .Net-Framework Version than the referencing project this error might occur.

ProjectName -> Properties -> Application -> Target framework

answered Jun 25, 2021 at 12:44

I had the same issue after I manually copied the referenced DLL file.
I solved it by displaying the reference properties in the Solution explorer then changing the Specific version setting from True to False and finally changing it back to True.
I rebuild and… it works just fine. Do not ask me why…

Note : I had to do the same for each project which had the CS0234 error message

PS : in my case Visual studio version is 16.1.6

answered Dec 30, 2019 at 13:25

I have some missing assemblies in my PC, and don’t have any idea how to fix it.

When I create a new ASP.NET MVC 4 internet application from template (using VS 2012) everything works fine. As soon as I try to integrate Web API controller I get a missing assembly reference error. For example, when I create application using ASP.NET 4 Web API default template and click «API» on the interface I get Compilation error:

Compiler Error Message: CS0234: The type or namespace name 'Description' does not exist in the namespace 'System.Web.Http' (are you missing an assembly reference?)

I have checked the assembly and everything seems to be fine. It’s in version 4.0. I have .NET framework 4.5 installed on my PC. Where should I look for the reason of the issue?

asked Nov 3, 2014 at 22:38

I saw this same error code (different missing reference) when compiling a PCL using msbuild but not when building via Visual Studio:

error CS0234: The type or namespace name 'Storage' does not exist in the namespace 'Windows' (are you missing an assembly reference?)

In my case it was caused by a ‘using Windows.Storage;’ statement that was not actually referenced by any code in the file. I removed the line and the error was fixed.

answered Jul 23, 2015 at 22:40