Look on your desktop. Do you see a folder called; Old Firefox?

https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

Hi, nothing like that on my desktop. I unfortunately hadn't backed them up first as I didn't see any warning that they'd all get lost!

As you did a refresh, it should be there.

These can't get your data back, but will help in the future.

These add-ons can be a great help by backing up and restoring Firefox

FEBE (Firefox Environment Backup Extension) {web link} FEBE allows you to quickly and easily backup your Firefox extensions, history, passwords, and more. In fact, it goes beyond just backing up -- It will actually rebuild your saved files individually into installable .xpi files. It will also make backups of files that you choose.

OPIE {web link} Import/Export extension preferences

Restore Bookmark Backups

To open the Bookmarks Manager, press the Alt or F10 key bring up the tool bar, and select Bookmarks. Hot key is <Control>(Mac=<Command>) <Shift> B.

Once the window is open, at the top of the page, press the button labeled Import and Backup. Select Restore. From the list, pick the file you want and click it.

Attempted to restore from a bookmarks backup Result: "Unable to process the backup file"

mwitthoft Please go to the top of any support.mozilla.org web page and use the Ask A Question link; https://support.mozilla.org/en-US/questions/new This will let us look at your system details. No Personal Information Is Collected.

"Old Firefox" trick didn't work. Deinstall/reinstall worked. HTH