Created attachment 112380 [details]
Trimmed thread dump
Not obvious to me from thread dump what is at fault. Something presumably has the read lock on the document (AnnotationView?). Does a caller need to manually acquire a document write lock before calling AbstractModel.endTransaction? Threading assumptions of XAM/XDM are not clearly documented that I know of.
*** Bug 211928 has been marked as a duplicate of this bug. ***
appears to be a duplicate of 202352 (in the sense that the fix for that bug fixed this one, not that they are the same problem)
*** This bug has been marked as a duplicate of bug 202352 ***