Consider that if an upgrade goes bad, a clean install might be your next step if you want all of the new applications to work. If you maintained a seperate /home partition, doing a clean install is painless as all old settings are maintained. You will need to reload all of your old applications, but once loaded, you will find they still have your old settings as if by magic. To use an exitsing /home partition, just edit the suggested partition setup to use your old /home partition and do not set it to be formatted and it is done.
Yes, you are right, by start up I receive notification about unability to reopen some previously (before upgrade to 11.4) opened tabs, and advise to start new session. But note rapidly disarrears, springs screen about error. There ware also some incompatible extensions. But I think tath they are disabled.
I am sorry I don’t understad what in what I must rename.
There is folder /root/.mozilla/ that has other conteint than /home/<user mane>/.mozilla. I Think, when Firefox is launched from “su”, it refers to first. May be simply accord the containt of the First to that of second.