NUnit - Unable to find test in assembly

Question

I have added a test to a class library in Visual Studio 2010. However when I try to load the assembly in NUnit I get the following error:

Test load failed!

System.ApplicationException: Unable to find test in assembly.

What could be wrong? The test has the following simple code:

using NUnit.Framework;

namespace Web.Tests
{
    [TestFixture]
    public class Test
    {
        [Test]
        public void ShouldLoadController()
        {
            Assert.AreEqual(1,1);
            Assert.IsTrue(true);
        }
    }
}

Answer 1

The answer seems to be to comment out the reference to 2.0 in the Nunit configuration file:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <startup useLegacyV2RuntimeActivationPolicy="true">
    <!-- Comment out the next line to force use of .NET 4.0 -->
    <!--<supportedRuntime version="v2.0.50727" />-->
    <supportedRuntime version="v4.0.30319" />
  </startup>
</configuration>

I'm not sure why this is necessary, as it appears that it should be able to select the correct run time.