I am running 78.10.0 on Ubuntu 20.04.4. Several months ago, I found that I had a beta version of Tbird and downgraded to 78. Because of the change in address book format between 78 and beta, the address book in 78 was blank. I found mab file from an older version of Tbird and decided that it was sufficient to use to build a new address book in sqlite. I got that done. (Don't remember the exact process, but it seemed to work.) Now I can read the address book, I can send messages from the address book, but if I compose a message and start to type a recipient name in the TO: field, Tbird doesn't check the address book. Nor does it add addresses for outgoing mail to the Collected Addresses book. Both of those actions have been set up in Preferences. Anyone know how to fix this? In the active profile, the abook files are abook.mab.bak, abook.sqlite, abook.sqlite-wal.