When I join a Google Hangout and try to share my entire screen, Firefox always prompts me whether to share a window or the entire screen. I always want to share the entire screen. But when I enable the checkbox for "Remember this decision" I get this warning: Firefox can not allow permanent access to your screen.

Why does this happen? Is it because I'm on a Mac, or is it specific to macOS Catalina?

  • I would think it is a security issue. – Steve Chambers Mar 13 '20 at 1:03
  • @SteveChambers I'm pretty sure there was a time when I didn't get this prompt, so I guess my question is what changed? – Nic Mar 13 '20 at 1:03

I don't think it's a Mac specific problem. I saw the same message on Windows and solved it with following steps:

  1. Write about:config to url searchbox and press Enter. You will see advanced Firefox settings.

  2. Create variable full-screen-api.approval-required and set it to true.

  3. That's it, you are now allowed to share your screen with Firefox.

  • 1
    This had potential, but I still get the same prompt after setting the variable as described here. :( – Nic Apr 10 '20 at 0:08

Would you please uncheck "Remember this decision" ? That should solve the problem ....

  • 1
    This prevents the error message but doesn't fix the actual issue. – nohillside Jul 7 '20 at 15:41
  • 1
    The question is about allowing permanent access. If you uncheck the option, the expected result will never be achieved by definition. Terrible answer. – Alessio Sangalli Aug 20 '20 at 20:46

Maybe you could post this question on the Mozilla support forum for Firefox, using this link :


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