I am trying one more time as nobody responded to my previous question. I need help restoring my Thunderbird profile to a new Windows 10 PC which was previously backed up by Carbonite from a Windows 8.1 PC. I've tried several things, including copying the backed-up .default profile into the new folder, which did restore all of my email, but the address book and local folders were not restored. A few other things: 1. The Carbonite backup did not include profiles.ini 2. I updated the existing profiles.ini to point to my previous .default file name rather than the new one created when I re-installed Thunderbird. 3. There are NO files with .mab extension in the profile. Instead, the two files that should be there (abook.mab and history.mab) have .sqlite extensions instead. I tried renaming them to .mab and restarting T-bird but the address book was not restored. Please - I need specific instructions. Thank you in advance!

Ok, I was just able to restore my local folders by editing the folder preference within T-bird. But I still don't have my address book back... :(

Do you think you could just create a new profile in Thunderbird? (troubleshooting information from the help menu and select the about:profiles link.

once in your new profile (with no accounts configured as it is a waste of time) click on the open button beside the profile folder. Close Thunderbird it must not be running Open the backed up profile folder in another window and open it to the point you can see the prefs.js file. Select all of the contents of the folder and all sub folders and copy and paste it into the new profile folder open in the other window. (unless you get errors about duplicate file you are not doing it right)

Start Thunderbird. I find it is much easier to put the stuff where Thunderbird expects it to be than try and force the program to look where you tell it.

I'm pretty sure that's what I already did. When I look in prefs.js, these are the lines for the address book: user_pref("mail.addr_book.view.startupURI", "jsaddrbook://abook.sqlite"); user_pref("mail.addr_book.view.startupURIisDefault", false);

Do you know where is 'jsaddrbook' defined?

Interestingly, I found this article (I am also on T-bird version 78.6): https://support.mozilla.org/en-US/questions/1295689 ("Address book not accessible after upgrade to Thunderbird 78") The OP resolved the issue by installing version 78.1. Maybe I'll try that. Older help documentation refers to address book files as abook.mab, not .sqlite. I'm wondering if that's the source of the issue.

Solved my problem! I found this article: https://support.mozilla.org/en-US/questions/1306681 My problem is more common than I thought. I found the two missing .mab files in my online Carbonite backup, downloaded them to the profile folder, re-opened T-bird, and ta-daaa! Address book is back.