I’ve been using the web clients of Proton Mail and Drive for a long time in Librewolf. Today it suddenly is stuck on the “Loading Proton Mail…” screen, getting no where. Still works in regular Firefox. Tried disabling both uBlock Origin and NoScript for the tab in case some settings there suddenly were changed, but did not help.

This is very frustrating.

EDIT: After a second reboot it now works again. Unsure why it took two reboots, I’m glad it works.