Put an asp.net user controls into a reusable dll

Question

I want to put some ASP.NET user controls, which we use in different projects, into a single dll so we can use them in every project with the same code base. I think I tried all possible ways I found on google, but when I add the generated dll in another project, Visual Studio can't find my controls from an aspx page. I wrote the register tag <Register Assembly="MyAssembly" Namespace="MyNamespace" TagPrefix="myPref".

When I start typing <myPref: IntelliSense doesn't give me any suggestions and if I start debugging anyway, Visual Studio can't find that tag at runtime.

Most of the documentations I read, are based on this (from 2011) and I followed the code guidelines:

https://docs.microsoft.com/en-us/previous-versions/dotnet/articles/aa479318(v=msdn.10)?redirectedfrom=MSDN

Another one, which uses a different way is this:

https://odetocode.com/blogs/scott/archive/2005/10/06/using-msbuild-and-ilmerge-to-package-user-controls-for-reuse.aspx

Here, I got the following error message:

The TargetPath parameter must be specified if the target directory needs to be overwritten.

I was able to fix this by specifying an absolute path instead of $(TempPath) in the .csproj file. After that, i got the next error: Visual Studio can't find the class types of my controls and pages.

In Visual Studio (2022), I tried every combination of checkboxes in the publish configuration dialog, but nothing worked.

I hope someone did this with current versions of Visual Studio and can help me.

Thank you!