Question: When running a web application project, at seemingly random times a page may fail with a CS0433 error: type exists in multiple DLL's. The DLL's are all generated DLL's residing in the "Temporary ASP.NET Files" directory.

Answer: 
None of this solutions worked for me. Compiling in "Release" mode worked, but when I switched to "Debug" I got umpteen of this error Messages.

I don't understand why, but a simple **restart of Visual Studio** was my solution.
I faced with the problem in compile time.

I *agree* with the **batch="true"** attributes, error is telling there exist 2 assembly

**Solution 1:** deleting one of them

**Solution2:** Configure one of them