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 in Visual Studio 2010 beta
Under <configuration> add:
<startup>
<requiredRuntime version="v4.0.20506" />
</startup>and under <runtime> add:
<loadFromRemoteSources enabled="true" />
Vincent Leung .NET Tech Clips 
True, that realy works. Just put it to NUnit.exe.config and not to config of your test project (I did that error on start) 🙂
Great tip, thanks. I found it also works in v2.4 (I’m using 2.4.8; updating to 2.5 is on the to-do list!).
Also, for VS2010 beta 2, the version number can be updated to 4.0.21006, but it seems that the build number isn’t checked as the beta 1 version number you listed above worked correctly for me too.
Thanks Vincent. I was starting to get worried that NUnit would not work with .Net 4.0
Hi, which config should I edit?
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Very Good!
Outstanding! Great hint.
Worked great! The current build number for released .NET 4.0 is “v4.0.30319.”
The actual .NET Framework version installed on your machine can be found from C:\WINDOWS\Microsoft.NET\Framework. Find the version of the .NET installed by looking into the folders.
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