Can't send email or see address book
A year ago, I copied the contents of my only profile in AppData/Thunderbird/Roaming/Thunderbird from my old PC to the same path in the new PC. Both were 78.6.1 (32-bit) at the time.
Behaviour has changed slightly with v91, so I thought I'd ask again. (original question here: https://support.mozilla.org/en-US/questions/1323164)
Working -I can see all emails/folders/accounts/etc -I can receive emails - all functions to do with receive seem to work fine
Not working -When I reply to an email, all fields look correct except that the window shows Write: (no subject) even though there is one. If I rewrite the subject that updates to the newly written one. The Send button is disabled, so can't send. -When I write a new email, when I type an email address into the 'to' field, the 'send' button becomes enabled, but pressing the button does nothing. I can press it lots of times - it doesn't seem to try to send - no errors. -My address books aren't showing although it does auto-complete typed email addresses. -Calendar is working correctly apart from when I dismiss an alert, the pop-up remains (empty but still there - I can close it). Mentioned in case it offers a clue.
I still have access to my old HDD, but now it's been a year I have downloaded thousands more emails.
Tried Copying and recopying the files. Deleting all adbook files and letting it rebuild
Noticed I have multiple prefs files (16). Some empty. prefs-15 is the second largest at 59kb with a date of 8/10/20 (when everything worked on old PC) prefs.js is 65kb with today's date.
I'd be happy to be talked through rebuilding a profile from scratch as long as I could get all my email back in and in the current sub-folder structure.
Currently, I'm using webmail to send, but I am starting to lose track of some important conversations as 'sent email' is never downloaded.