I had a load test that used a coded web test. At some point the coded web test changed, i.e. this line was added:
Outcome = Outcome.Fail;.
After this change the test stopped working – it always ended with error message: ‘User aborted test run’. Apart from that each iteration of the web test produced MethodAccessException: Microsoft.VisualStudio.TestTools.WebTesting.WebTest.set_Outcome(Microsoft.VisualStudio.TestTools.WebTesting.Outcome).
The reason for the problem was I was using Visual Studio TS 2008 without SP1. Once I installed the SP1, which must have updated mstest, the test started running successfully again.
The key point here is before SP1 Outcome was read-only property, which I learned there.