NUnit isn't running Visual Studio 2010 code

Question

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?

Answer 1

I found usefull to start from NUnit Application Template. It support VS C# Express, allows debugging tests and contains precompiled NUnit for .NET 4.0. Thank to author new test project gets ready with one click.

Answer 2

If you experience this issue after upgrading to nunit 2.5.5 then you will need to upgrade nant to the latest version for me it was .91 alpha.

Answer 3

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" />

Answer 4

You don't have to modify any file

just open this file and everything will work just fine

C:\Program Files (x86)\NUnit 2.5.10\bin\net-2.0\nunit-x86.exe