uBO extension doesn't start on Firefox launch

[Cromemco]

Probably an isolated issue, but I have an older Mac running Firefox 115.23.0esr. uBO doesn't start automatically when I restart Firefox. Going into the add-ons window, it says uBO is on, but the icon doesn't show on the toolbar. If I manually toggle it off and back on, then uBO appears, but it disappears again at the next launch.

[krystian3w]

Test with a fresh profile from about:profiles (mark the old profile as default).

The new profile can be started with the -P parameter in the Firefox shortcut.

If it doesn't disappear, then maybe the old profile is corrupted and it's time to make a copy of your valuable stuff and add-on configuration in case the Firefox refresh mechanism fails https://support.mozilla.org/en-US/kb/refresh-firefox-reset-add-ons-and-settings (e.g. the profile will not work, you will lose passwords, bookmarks or history in it or a copy will not be placed on the desktop).

Later you can check if the RAM or disk is dying (maybe an important file is saved in a corrupted zone and you have too many of these zones).