Ok, I am seeing this all the time and finding the solution in Google is next to impossible, so I am hoping this gets indexed high so others can find it in the future.

If you try to change the property settings in the .TestRunConfig file in your project and you have any of the following product types in your solution:

• VS2008 Database Edition GDR
• Silverlight
• WiX Installer Project

the dialog box closes automatically.  No crash, no error, just a nice clean close.  This also happens when you try to run the "Create Unit Tests" wizard by right clicking on your classes.

The issue is with the OutputLoc property for these project types, because they don't support the OutputLoc concept, they just throw a NotImplementedException whenever they get called, and the dialog does not seem to handle that well.  There are two solutions to this problem:

• Unload the offending projects from your solution, do what you need to do, then load them back up.
• Install the fix described in KB 962866