Details: No settings were manually altered during the upgrade. Network connectivity is fine and all other programs, including browsers (same pages), work as expected. Furthermore, the issue affects pages loaded from localhost as well! Most of the time FF displays "Performing a TLS handshake...". Occasionally the FF UI freezes totally for a few seconds. What does not help: - creating a new profile - network settings: no proxy - disabling all add-ons - clearing cache What helps: - safe mode (everything works as expected) - refresh (but only until next logout / reboot) - keeping vpn off (openvpn) Turning vpn off does not help, but keeping it off seems to keep FF working as expected over logout / login. Hence, turn vpn off, refresh FF, keep vpn off seems to help. Any ideas how to solve / debug the problem? As such FF is more or less unusable, since running it in safe mode all the time or refreshing it after every login is not practical...