More info please! ;-/ What OS? What version of Firefox? Do you have the same issue with Firefox in Troubleshoot Mode? https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode#w_how-to-start-firefox-in-4troubleshoot-modesf5safe-modesf

I am using windows 11 and firefox version 136.0.4, I get the same "gagh your tab crashed" in troubleshoot mode. I have uninstallled reinstalled, I have cleared up start up cache, and I have tried refresh firefox and still the same thing keeps happening. This horrible situation just occured out of the blue yesterday and is really testing my patience, can FIREFOX please help me. Many thanks

If Windows Pro version, try testing in Windows Sandbox (VM) to see if you have the same issue. https://www.howtogeek.com/399290/how-to-use-windows-10s-new-sandbox-to-safely-test-apps/ Are you running any security software besides MS Defender? Where did you get Firefox from?