Firefox 115.10esr auto update just reset all preferences to default... Grrrr...

[JonJ]

Firefox 115.10esr auto update just reset all preferences to default as well as adjusting various toolbar appearances and has a strange dark outline around tab headers which moves from one window to another. That's 3/4hr wasted this morning sorting out the mess...

[jscher2000]

Sorry to hear about that. Maybe your Firefox performed a Refresh/Reset/Tune-up during your update. Did it mention anything like that? Did a new "Old Firefox Data" folder appear on your system desktop?

[JonJ]

The update auto-installed on firefox start-up following a crash. No new "Old Firefox Data" folder appeared, but there was an extra 'welcome / get started' (or similar) browser tab appeared alongside a restore previous windows/tabs and 'new' blank tab.