I'm trying to load a Visual Studio 2010 beta dll into the NUnit GUI. I get a popup error.
This assembly is built by a runtime newer than the currently loaded runtime and cannot be loaded. You may be attempting to load an assembly build with a later version of the CLR than the version under which NUnit is currently running.
How do I force an executable to run under .NET 4?
I've downloaded the NUnit 2.5 source and opened the VS2008 solution in the VS2010 beta. Once the conversion finished I opened all the projects and changed the target framework setting for all the projects to ".NET Framework 4.0". I then built the solution without any errors. I can now use the NUnit GUI app to run tests built for .NET 4.0. I've not done exhaustive testing of this build so there may be problems, but for my purposes it works fine.
Update: It is not necessary to rebuild NUnit. I discovered that if you add the following to the relevant NUnit config file you can run a test dll built for .NET 4.0.
Under <configuration> add:
<startup>
<supportedRuntime version="v4.0.30319" />
</startup>
and under <runtime> add:
<loadFromRemoteSources enabled="true" />
The proposed solution worked great for getting NUnit to run. Unfortunately, when I then got to my code coverage step, NCover started giving me:
Profiled process terminated. Profiler connection not established.
The best solution I found to this was to just use the "-x86" version of NUnit with NCover:
NCover.Console.exe nunit-console-x86.exe --additional params--
Works now.
I ran into the very same error message while running NUnit 2.4.8. As I had not upgraded in some time I installed the current NUnit (v2.5.9) and found that it now supports VS2010 assemblies. So if you have newly encountered this error check your NUnit version: as of December 2010 (or so) the only thing you need to do is upgrade NUnit.