Going to my "Activity" tab on stackexchange.com results in an "Oops! Something Bad Happened!" server error. This only happens on my page, not that of anyone else. Other tabs are unaffected. I can view my inbox and achievements in the top bar normally.
This has been happening since Oct. 1, 2021 at least (I don't check that page often enough to know when it started). I've done a lot of weird stuff with the Stack Exchange software, but I can't think of anything that would cause this page to error out. Maybe it was because I tried to send a CM message from a Team?