Messages cannot be moved between folders and the only option is to shutdown/restart Thunderbird Junk mail stops being moved to the junk folder. I attempt to delete the message from the inbox, the message gets changed from status "not read" to "read", but the message does not get deleted (I think this is because the message cannot be moved). Move a message manually, click, hold, drag to another folder stops working. All folders have been compressed. My inbox was quite large - I recently started archiving those messages left in my in-box to archive folders and re-compressed all folders. Scenario still occurs. I changed a few junk settings a few days ago and the problem started occurring (unfortunately I do not remember the specifics of my changes and did not write them down).