User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/46.0.2490.86 Safari/537.36 Steps to reproduce: Following is modified content from the report at Mozilla Support: 1) on dragging to folder, emails still highlighted, no apparent action occurred for several minutes; now happening almost daily. No detectable change in network integrity, no VPN. Win 7, Thunderbird config in enclosure Actual results: 2) usually, program had to be closed (but not always due to a hang), then re-opened; all text disappears from 'Subject', 'From' and email body, except 'Date' which shows date and time, 3) at this time, destination folder may not hold emails (I think), but later they did after restarting Thunderbird, 4) sometimes program hangs, others not, 4) IMAP email account accessed through a browser shows no record of corrupted emails, but sometimes did after Thunderbird restart, 5) used Thunderbird in POP3 account for years with no similar issue, 6) 'email source' (View-Message Source) shows only, e.g. as below: From - Thu Oct 29 09:26:00 2015 X-Mozilla-Status: 0001 X-Mozilla-Status2: 00000000 X-Mozilla-Keys: Expected results: 7) email ought to have been moved to destination folder and removed from 'Inbox', 8) should contain all email contents unmodified, 9) 'Inbox' at server should not hold email skeletons, but will reflect moves by 'deletions' Current workaround: a) open browser and login to IMAP account, b) move target emails from 'Inbox' to other folder and mark all as unread, c) close Thunderbird, d) move target emails back to 'Inbox', e) reopen Thunderbird, f) dragging email to folder now works as advertised. Any suggestions for a fix, or recommendations? Thanks!