I tried 3.0 beta and build #452, but I wanted to revert to 2.5.2. After doing so, I can't use the Test Runner. Every time I try to run any tests, I get a NullReferenceException. I reported it to Jira twice via R#, but I can't remember the # or find it in Jira right now.
Has anyone successfully reinstalled 2.5.2 after trying 3.0 beta or later builds? If so, did you do anything special that I might not have thought to do?