To make it worse... Even if I entered a login manually, the password disappears on a next/second attempt. Sorry, but I'm sick and tired of Firefox at this point.

Sounds like you got sync issues with your devices causing this problem. Are you sure those devices are connected correctly.

No issues with the other devices. On top of that you need to verify twice in order to even use your Firefox account (again). Why is it even possible that all my logins disappear?! The problem started after the update to 102 yielded the result that the browser wouldn't start anymore.

I erased Firefox from my system entirely and installed a new version of 102 DE 64bit. Trying to start the program - that failed! One instance of the program was running with very high usage of memory resources (as shown in the task manager). Could it be that 102 is a Trojan of Mozilla? I even had to log in from another browser to access and use this forum.

No help. Thanks Mozilla.

Installed version 102 again in a different folder and it worked until I restarted windows 10 64-bit. Thereafter Firefox won't start again, even though once instance appears to be active. High CPU usage. Program won't start.