Changes affecting Adobe Flash on Firefox for Mac

Revision Information
  • Revision id: 210629
  • Created:
  • Creator: AliceWyman
  • Comment: {warning} Adobe Flash EOL January 2021
  • Reviewed: Yes
  • Reviewed:
  • Reviewed by: AliceWyman
  • Is approved? Yes
  • Is current revision? No
  • Ready for localization: Yes
  • Readied for localization:
  • Readied for localization by: AliceWyman
Revision Source
Revision Content
Adobe Flash support endedwill end in January 2021. To learn more, see End of support for Adobe Flash.
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.