While away from my computer for a few days, Thunderbird stopped retrieving new emails. I noticed this when I returned. I'm using imap to download from the server. Logging in to the server via browser shows that there indeed new emails. Quitting Thunderbird and restarting results in showing old emails and a spinner (slider?) on the Inbox tab that never stops. I have not changed configuration recently (I was away when this started). I followed a suggestion to delete cert9.db, key4.db, and logins.json. Doing this and restarting changed nothing. My understanding is that this should have deleted my server password information, but I was not prompted for a password on restart. I have uploaded a snapshot of the "Troubleshooting information" tab to pastebin: https://pastebin.com/fsB64yiu