NUnit BadImageFormatException

In a project of mine, NUnit suddenly started to warn that something’s wrong with the assembly. Turns out that accidentally disabling architectures is a bad thing.

I use NUnit in all my projects. It works amazingly well in all of them. In this new project, it worked great at first, then suddenly starting failing with the following errors:


I tried to solve this problem for a long time, but eventually gave up and recreated the project from scratch, which solved the problem.

After doing so, I sat down with a colleague and had a look at the original, still failing project. We found that one architecture has been accidentally disabled. This caused the test project to fail when it tested the project.