I just got a very odd error message in 4.1 RC2:

I was not doing anything with Logos. Logos was running in the background and I had done nothing with it for hours. I was in my Web browser at the time.
The odd thing is that I can still browse books, search, open books, etc. even though this error is still showing. Sorry, but I do not have debugging on, so I cannot show you any error logs. Also a crash log file was not created.