Thunderbird is running (apparently properly) on both my (old) HP laptop, and on my (new) Samsung laptop. But the Thunderbird address book on the Samsung only shows the email addresses associated with emails that have been sent or received since I installed Thunderbird on the Samsung. It does not include the rest of my address book. Similarly, it only contains the emails that have been sent or received since I installed Thunderbird on the Samsung. When I follow the instructions to open the (Thunderbird) profile folder, I get a message that says “C:\Users\User\AppData\Roaming\Thunderbird\Profiles\fbclykvb.default-esr is unavailable.”

With help from Currys (where I had bought the Samsung), we were able to copy the (ApsData) Thunderbird folder from the (old) HP laptop to the (new) Samsung) laptop. (They also ran something called mailmerge, but I didn’t follow the precise details.) I can now find the Thuderbird folder in the AppData/Roaming folder. In the Profiles, there are 2 subfolders, hw7ms2fs.default-release and w1a31rjn.default. w1a31rjn.default has only one file – times.json hw7ms2fs.default-release has lots of subfolders and files, but no file named fbclykvb.default-esr. Thunderbird is still working properly on the Samsung, but I still can not access my larger address book, or emails that were receive or sent by Thunderbird on the HP. How do I fix it? The people at Currys tried to help, but they don’t know much about Thunderbird, and said I needed to get support from Mozilla.