Photo didn't link. Trying again...

The screenshot failed to load, but I've got a pretty good idea of what's going on here.

Would you try this :

Type in the address bar about:config (press Enter) Promise to be careful, if asked) Type and look for the preference : security.sandbox.content.level and set its value to 1 (one) (default value is 3 )

Are things back to normal now, or still no joy  ?

MuddyDirt said

Photo didn't link. Trying again...

Yep, just as I thought - we're seeing a lot of those these days.

Yes, that fixes the problem. Anyone figured out why this is happening yet?

I have a suggestion as to the nature of the problem. I wonder how many Mac users are running Suitcase Fusion for font management.

May be worth a look.

MuddyDirt said

I have a suggestion as to the nature of the problem. I wonder how many Mac users are running Suitcase Fusion for font management.

Very astute  ! Maybe you'd like to post something here :

https://forums.extensis.com/c/font-management/suitcase-fusion-7-mac-os

Well, if I have to choose between Firefox and Suitcase, I have to choose Suitcase.

I do Electronic Pre-Press and Fusion is a must for my font management. It automatically loads fonts when I open files sent in by my customers. Installing fonts for every customers file would make me go insane (or at least more insane).

Maybe the Mac version of Firefox could somehow "look" to see if Fusion is present and automatically set the security to 1 (at least until they figure out a more permanent solution).