After automatic update (June '19), page up and page down buttons don't work
Caret browsing isn't on. The arrow keys still work, and page up/down work in other programs. A couple of other weird quirks also appeared after the update (Firefox seemed to have forgotten my preferences and I had to reset them twice to get them to stick), but it's only the page up & page down one that's still unsolved.
Wšykne wótegrona (1)
Does the Space and Shift+Space alternative work? Does Ctrl + PageUp/PageDown work to switch between tabs or dies this fail as well?
If you lost personal data then it is possible that a new default-release profile folder has been created. See "Determine if Firefox has created a new profile":
You can open the about:profiles page via the location bar to check whether multiple profiles are present and what profile Firefox currently is using.
- Do NOT click any Remove button on this page.
- https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles
Firefox 67 and later can use a dedicated profile for each of the Firefox update channels and will lock the profile, so it can only be used by Firefox in a specific installation folder. For Release versions this profile would be a xxxxxxxx.default-release profile, profiles used in older Firefox versions usually used a xxxxxxxx.default profile (a refresh adds a time stamp).
- https://support.mozilla.org/en-US/kb/dedicated-profiles-firefox-installation
- https://blog.nightly.mozilla.org/2019/01/14/moving-to-a-profile-per-install-architecture/
Start Firefox in Safe Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration is causing the problem.
- switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Themes
- do NOT click the "Refresh Firefox" button on the Safe Mode start window