Firefox not loading/responding

[tinman1]

I had signed in to my Firefox profile previously then signed out and signed in with my sister's profile. This was for her to borrow my MacBook Pro as her Windoze laptop was on the fritz. Now I find when I try to open Firefox I just get the spinning beachball ie 'not responding' dialogue then have to force quit. So I deleted all the remains of Firefox (using the excellent Appdelete) and tried re-downloading and installing. Same issue. Any ideas as to how to cure this? I'm using a 13" M1 MacBook Pro running Big Sur. I've already tried Disk Utility - read out was OK no problems found. I've tried Cocktail but no difference.

 

[bogdanw]

Try to right-click → open Firefox or try Firefox ESR https://www.mozilla.org/firefox/all/#product-desktop-esr

 

[tinman1]

THANK YOU - that seems to have worked.