I've seen another report about this issue, so there might be compatibility issues on Mojave.

• /questions/1234151 Firefox windows is all black nothing showing

Are you possibly using Mojave Dark mode?

I'm not seeing this reported on Bugzilla, so maybe file a bug report.

• Bug 1466336 - (mojave) [meta][10.14] macOS "Mojave" tracking bug

(please do not comment in bug reports
https://bugzilla.mozilla.org/page.cgi?id=etiquette.html)

Entering about:blank takes me to the page, but it is still totally black. Same for any other page I visit. I can tell by right-clicking the firefox icon.

• I reset my PRAM and SMC, both changed nothing.
• The black screen shows in both light/dark mode, but the guest account can show firefox without problems in either mode.
• I rebooted without opening work on launch. I even tried deleting firefox, rebooting, and reinstalling.
• I used Cocktail (12 b2) to clear caches, logs, and other misc stuff.
• I also tried deleting cache with CCleaner for mac.

I'm pretty sure it's a bug at this point, so I'll just wait til the next update and report back when I get the chance.

Edit: As another person pointed out in a bug report, a terminal command is a workaround for fixing this issue. This command keeps the bar/dock as dark, but the rest of MacOS will be bright (finder, notification center, safari, etc. This is a TEMPORARY solution, so please do not mark this as closed until it is properly resolved.

Enter: defaults write -g NSRequiresAquaSystemAppearance -bool YES killall Dock killall Finder

Restart firefox and it will be visible. Change YES to NO to reverse changes (use killall or restart).

Try disabling graphics hardware acceleration in Firefox. Since this feature was added to Firefox it has gradually improved but there are still a few glitches.

You will need to restart Firefox for this to take effect so save all work first (e.g., mail you are composing, online documents you're editing, etc.,) and then perform these steps:

In Firefox 54 and below:

1. Click the menu button and select Options (Windows) or Preferences (Mac, Linux).
2. Select the Advanced panel and the General tab.
3. Uncheck Use hardware acceleration when available.
4. Close Firefox completely and then restart Firefox to see if the problem persists.

In Firefox 55 and above:

1. Click the menu button and select Options (Windows) or Preferences (Mac, Linux).
2. Select the General panel.
3. Under Performance, uncheck Use recommended performance settings. Additional settings will be displayed.

   

4. Uncheck Use hardware acceleration when available.
5. Close Firefox completely and then restart Firefox to see if the problem persists.

Did this fix your problems? Please report back to us!

If the problem is resolved, you should check for updates for your graphics driver by following the steps mentioned in these Knowledge base articles:

• Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

• Upgrade your graphics drivers to use hardware acceleration and WebGL

or see this page:

• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems#w_turn-off-hardware-acceleration

To test the Hardware acceleration solution, I first disabled system-wide dark mode using the terminal command I posted above:

• defaults write -g NSRequiresAquaSystemAppearance -bool YES

I then went into Firefox and disabled Hardware acceleration without changing any other settings, then quit. I opened again to confirm the changes were saved and quit.

I reset the terminal command back to its original value with:

• defaults write -g NSRequiresAquaSystemAppearance -bool NO

I opened Firefox and it still shows up as all black. This is true in both dark/light mode. It is also worth mentioning: While system-wide dark mode is disabled (terminal command), *Firefox responds to the mac system preferences dark/light settings.

• Firefox only turns completely black when system-wide darkness is enabled (default terminal command, dark finder, mail, notification center, etc.).

More information:

• Bug 1493330 - Firefox shows black window and no dialog text in macOS Mojave

(please do not comment in bug reports
https://bugzilla.mozilla.org/page.cgi?id=etiquette.html)

A few updates on things that did not work:

1. Updating to Mojave 14.1 (public release and public beta as of today). 2. Reinstalling Mac OS while preserving user data. 3. Deleting user preferences folder, app cache data, etc. 4. Updating firefox to 63.0

The only solution that worked for me is to completely wipe my Mac OS partition and install all of my data manually (I don't use a time machine backup).

Before I tried this fix, MS office apps no longer had text visibility issues in boxes. After freshly installing, Chrome and other apps (app cleaner) do no have the visibility issue anymore. Perhaps it was likely leftover system junk from high sierra.

Anyways, I hope this helps someone else experiencing this.