We're sorry to hear that Firefox is crashing. In order to assist you better, please follow the steps below to provide us crash IDs to help us learn more about your crash.

The crash report is several pages of data. We need the report numbers to see the whole report.

1. Enter about:crashes in the Firefox address bar and press Enter. A list of Submitted/Unsubmitted Crash Reports will appear, similar to the one shown below.
2. Copy the 5 most recent Submitted Report IDs that start with bp- and then go back to your forum question and paste those IDs into the "Post a Reply" box.

Note: If a recent Report ID does not start with bp- click on it to submit the report.

(Please don't take a screenshot of your crashes, just copy and paste the IDs. The below image is just an example of what your Firefox screen should look like.)

Thank you for your help!

More information and further troubleshooting steps can be found in the Troubleshoot Firefox crashes (closing or quitting unexpectedly) article.

Hello Paul,

thank you for that. I have just checked this and there are no logged crashes at all. The program does stay open, the window just disappears and does not enter full screen mode. I have found many threads about the issue with the toolbar issue some people were having but this is completely different. It is hard to explain so if allowed I do have a screen recording of the issue on an iCloud share link.

The best I can explain in words is that when attempting to enter full screen mode from desktop on Firefox the program freezes and never does anything, the only time I have gotten anything to happen was when I click on one of the OS drop down menus the menu goes clear as shown in screenshot 1 or my original post and the window completely disappears.

Please let me know if I can attach the screen recording link to my next reply.

Thank you for your assistance

This thread seems to have the same issue I am currently dealing with. Please see attached link. [[Mac OS Montery (and before):Firefox is freezing and then crashing whenever going full screen.]] https://support.mozilla.org/en-US/que.../1377103 The troubleshooting from this thread did not work in my case.

Here are some steps you can try to resolve the full-screen freezing issue:

Update Firefox: Ensure that you're using the latest version of Firefox. Outdated versions may have bugs that have been fixed in newer releases.

Update MacOS: Make sure your MacOS is up-to-date. Sometimes, system updates can resolve compatibility issues with third-party applications.

Extensions/Add-ons: Disable any browser extensions or add-ons one by one and try entering full-screen mode after disabling each one. Sometimes, extensions can conflict with full-screen functionality.

Safe Mode: Launch Firefox in Safe Mode to rule out any third-party interference. To do this, go to the Firefox menu > Help > Restart with Add-ons Disabled.

Clear Cache and Cookies: Excessive cache and cookies can sometimes cause issues. Go to Firefox preferences, find Privacy & Security, and then Clear Data. This will remove cached web content and cookies.

Hardware Acceleration: Experiment with hardware acceleration settings. Go to Firefox preferences, search for "Performance," and disable or enable hardware acceleration to see if it makes a difference.

Create a New Profile: Sometimes, issues are profile-specific. You can create a new Firefox profile to see if the problem persists there. To do this, open Terminal and run: open -na "Firefox.app" --args -ProfileManager, then create a new profile.

Reset Firefox: As a last resort, you can reset Firefox to its default settings. This will retain your bookmarks but remove customizations and extensions. In Firefox, go to Help > Troubleshooting Information, and click "Refresh Firefox."

Check System Preferences: Verify your MacOS system preferences for display settings, resolution, and scaling. Make sure everything is set correctly.

I have tried all the above troubleshooting suggestions, and still it seems to not work. I also checked to see if full-screen-api.macos-native-full-screen is marked as true and it is. I also do not have any add ons or extensions on Firefox as of yet.