All extensions are "can't read or change data"

"Can't read or change data on this site" usually means that the extension does not have permission to make changes to the page or to intercept data flowing into and out of the page. If you are seeing it on sites where the extension definitely should work, hmm, I wonder whether a file storing permissions has become corrupted somehow.

Let's circle back to the other issues first.

(1) Profile not found

This could occur if an index file named installs.ini or profiles.ini retained the unique folder names of your old default profile, but that profile folder was moved or deleted. Does that sound like an intentional change? Or possibly an unintentional data loss?

(2) Recreated the profile and problem continue

Could you describe what you did? Did you use Firefox Sync to repopulate profile data, or a backup from Time Machine or an external data store, etc.?

(1) Unintentional data loss after Mac Osx had a "brian fart".

(2) Did lots of things but the last this was to delete Firefox and reinstall from scratch. I assume that Firefox Sync resynced from my firefox on my iphone.

Maybe I should try a reinstall again?

thanks, FJohn

••• ••• 2026-Oct-30 1219

Uninstalled all. Restarted firefox. Reinstalled the ones I use the most. Restarted. Appears to be working. Not sure why. Not sure if it'll stick, but here goes.

Restarted everything cold including macosx. Seems to be working correctly, Maybe it was just "evil spirits" for Halloween? As good an explanation as when a doctor uses "ideopathic" as Greek for "I hove no idea". Sigh! Laugh! Thanks for listening and suggesting. FJohn

2026-10Oct-30 1434

Thank you for reporting back. Sometimes the old cliché "Have you turned it off and on again" actually works.