First, I am not a Linux guru, although I do use it on occasion. From other posts on this forum, I am aware that Thunderbird is not consistently installed in the same location, but is somewhat dependent on the repository from which it came. So, here are my thoughts: - locate the position of the active profile: to do this, click help>troubleshootinginformation, scroll down to profile folder and click 'open folder' You are now in the profile. exit thunderbird, back up one level so that you are outside the profile. - copy that exact profile folder elsewhere on drive or to external media. - after copying review what you copied to ensure you have the desired data, including your addressbook (abook.sqlite) and your accounts, whether on the Mail or Imapmail folders and local folders in the Mail\Local folders folder. - now uninstall and reinstall according to your needs. If the prompt allows keeping the data, do that, if only as extra security - start thunderbird. if all is there, that indicates the new version installed with same settings. If not, click help>troubleshootinginformation, scroll down to 'profile folder' and click 'open folder' and exit thunderbird. you are now in the new thunderbird's profile. back up one folder so you are outside the profile. Now copy/past the profile you previously saved into that profile folder. Now restart thunderbird.

Thanks very much for this. I am still nervous, mainly due to the nightmare I had converting and setting it up once already! But sounds like good advice. Note: That process doens't work to open the profile folder. Not sure how to find the profile folder otherwise. If i click nothing happens, which I am sure is related to the reason I have to do this uninstall/reinstall process. Simply put: TB can't interact with the system properly (yes, due to the type of install I did, which doesn't allow access to system files, default apps etc)

I first noticed the problem when I couldn't open PDFs in emails other than with TB (undesired). I choose "System Handler" in settings, then when I double click nothing happens, so have to save before I can open it from Files app. Same goes for images, videos, all files.

I learned (total noob to Linux here) that it's because I installed TB from the Fedora repository, which limits it's access to other files outside of its container. If I uninstall and install from FlatHUB (where Mozilla packages their own installer) these problems will go away. Not being able to click "profile folder" is (I'm sure) the same issue.

So I guess, if I can just suss where my profile folder is, i think you're sayig I can just backup that entire folder to other media, and i at least should be 'safe' in terms of those local folders and emails, which is the main concern. I dont have any contacts set up yet, or calendars, just one imap account, my preferences/settings, and a HUGE list of nested local folders (25+ years of email!)

thanks

Just be aware, that flatpaks are sandboxed. I don't understand the intricacies, but the data from your old install will probably have to be copied into the sandbox to be seen and updated.