In #7274 only the Changes panel 'Local' tab is usable for me. The 'Repository' and 'Incoming' tabs both create errors as soon as they are selected, and the panel remains blank.
This is in a completely clean install of #7274, with an existing project using CVS. I can do other CVS operations OK, but the 'Changes' panel is broken.
I had this problem in #7269, but deleting the caches and restarting IDEA fixed it. This fix doesn't work with #7274.
I have reported the errors via the 'Blame' dialog.