Start Firefox in Safe Mode {web link}

A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?

No, it seems to be okay when Firefox is in Safe Mode.

It could be the work of one of your add-ons, or it could be Hardware Acceleration. How to disable Hardware Acceleration {web link}

Type about:addons<enter> in the address bar to open your Add-ons Manager. Hot key; <Control> (Mac=<Command>) <Shift> A)

In the Add-ons Manager, on the left, select Extensions. Disable a few add-ons, then Restart Firefox.

Some added toolbar and anti-virus add-ons are known to cause Firefox issues. Disable All Of them.

If the problem continues, disable some more (restarting FF). Continue until the problem is gone. After, you know what group is causing the issue. Re-enable the last group ONE AT A TIME (restarting FF) until the problem returns.

Once you think you found the problem, disable that and re-enable all the others, then restart again. Let us know who the suspect is, detective.

I only have 4 add-ons, and when I disable them all and disable hardware acceleration the probelem persists.

Let me guess: Shadow Fox.

See https://www.reddit.com/r/firefox/comments/dlxfoe/site_information_is_bugged_full_of_symbols/

Do you use userChrome.css and userContent.css files from the ShadowFox dark theme? Make sure you update them to the latest from time to time to keep up with changes to Firefox. The problem in your screenshot seems to have first popped up in Firefox 70 and hopefully is fixed by now.

• https://overdodactyl.github.io/ShadowFox/

• https://www.reddit.com/r/firefox/comments/dmgjgj/noticed_this_morning_drop_down_for_flash_perms/

I installed Shadow Fox on my previous Mac, but I haven't installed it on this new one. However, I did copy my profile over so I bet there are remnants of Shadow Fox still in it.

And I confirm this by creating a new profile and it doesn't have that issue.

Is the problem solved? If not, you can continue to ask questions and we can solve them together