We are running R# 5.1.3000.12 with VS2010 and are experiencing a strange problem with the test runner. For at least one specific solution it refuses to run any tests, however the same projects are included in other solutions where they are running fine. All tests show up in the unit test sessions window as expected, it shows hourglasses while building and then the progressbar turns green with no report of number of tests run, succeeded and failed. All tests are marked with a grey dot indicating they have not been run. We are using MsTest, and the Visual Studio test runner executes the tests fine. I have tried to enable breaking on all CLR exceptions thrown, but it doesn't seem there are any, and nothing special is showing up in the output window. The solutions are are using different testsettings files, but there doesn't seem to be any interesting differences on them, and as mentioned the VS test runner executes the tests fine.
Any input on how to solve this?