I-Firefox Isithangami Sokwesekwa

I have Firefox 100.0.1 on my Mac desktop, and Firefox 100.0 on my MacBook Pro laptop. I can no longer access my Microsoft OneDrive account via the web on my desktop, but I still can do so on my laptop. I have gone through your posted troubleshooting steps for Firefox on my desktop, to no avail. How do I get my desktop back to version 100.0 so it will work again? I can access my OneDrive account via the web on my desktop when I use the Safari browser, so the issue is definitely with Firefox version 100.0.1, and not with my desktop.

Suddenly, when I search the web with a topic search term, e.g. "thrombin", I get the error message: 'The page you are looking for cannot be displayed because an invalid method (HTTP verb) is being used.' Can you help me resolve this problem?

I have an Apple M1 chip machine. Firefox isn't working. Happened before, downloaded new Firefox. Problem has recurred and I cannot remove old Firefox. I remove it from applications, reinstall, and then it tells me I already have Firefox open.

In the last few weeks FF has started running really slow. Launch takes 4-5 minutes, the browser won't navigate to any webpages. Preferences can't be opened. The force quit window show the app to regularly moving in and out of a "not responding" state. I had version 95.0.2 installed (the latest). I'm running OSX 10.15.7 (catalina). I uninstalled an reinstalled 95.0.2 and the same problem persisted. I downgraded to 94.0, and created a new profile in the process, and still had the performance problem. Chrome and Safari don't have the problem, and my machine is running as expected with all other apps. I don't have any sites load upon launch. I have 16G of RAM.

Since I can't open prefs, I can't purge caches or anything like that.