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.

1. Enter about:crashes in the Firefox address bar and press Enter. A Submitted Crash Reports list will appear, similar to the one shown below.
2. Copy the 5 most recent 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.

Does it look like one of those extortion pages that tries to prevent you from leaving the page until you pay them? Unfortunately, those sites seem to find new ways to do that from time to time.

I'm not very familiar with Mac, but can you "force quit" Firefox? Here's an Apple support article: https://support.apple.com/en-us/HT201276

If that works, to restart Firefox, try using a link instead of the regular Firefox icon. That should hopefully prevent the bad page from being automatically restored, or at least make it easier to access Firefox settings.