I get this sort of thing fairly often. Sometimes it's part of the message topic list, sometimes it's the vertical scrollbar for the message topic list, but it seems to always be related to the message topic list, and it happens after running a search. This screenshot is after a search. Haven't been on the forum much the last year, so I don't know if this has been mentioned before, I couldn't find anything about it. I've also had this happen with previous versions.
Using 2.5.61.
Monte
Hi Monte,
I'll pass it on to the developer.
Cheers,
Wilson.