Changes affecting Adobe Flash on Firefox for Mac

This article is no longer maintained, so its content might be out of date.

End of Flash support: Like other browsers and Adobe, Firefox ended Flash support at the end of 2020. Please see End of support for Adobe Flash for more information.

This article only applies to Firefox for Mac.

Starting with Firefox version 62 for Mac, Adobe Flash applets will be run in a more secure mode using process sandboxing.

The sandbox is known to prevent the following features from working:

  • Print to PDF from the Flash print dialog
  • Print to Open in Preview from the Flash print dialog
  • Quicklook in the File -> Open menu
  • Saving files from a Flash applet
  • Flash applets downloading and running the Adobe Air installer
  • Flash triggering Adobe Air applications to run

To disable the Flash sandbox in Firefox, follow these steps:

  1. Type about:config in the address bar and press EnterReturn.
    A warning page may appear. Click Accept the Risk and Continue to go to the about:config page.
  2. Find the preference dom.ipc.plugins.sandbox-level.flash and double-click itclick the Edit Fx71aboutconfig-EditButton button.
  3. Enter an integer value of 0 (zero) and click OKon the checkmark Fx71aboutconfig-Checkmark to save the change.
  4. Quit and reopen Firefox so that the change will take effect.

These fine people helped write this article:

Illustration of hands

Volunteer

Grow and share your expertise with others. Answer questions and improve our knowledge base.

Learn More