Partial error(?) messages popping over documents

Starting with 3.8.1, I am seeing DTTG frequently popping up what appears to be partial error messages over the top of whatever I’m reading. Example below.

What is the purpose of this? From the fragment that’s visible, it looks like this may be related to a missing file, which used to be surfaced in the sync logs. But I can only see part of the message, so I’m not sure. It is quite frustrating to have an unactionable, unreadable message popping over my documents every few minutes while I’m trying to read. Is there a way to suppress this or have it surfaced in a way that doesn’t impair my ability to read a document?

Yes, that is surely a missing manifest.
On DEVONthink To Go’s databases screen, select ? > Contact Us to start a support ticket. Include a full-resolution uncropped screen capture. Thanks!