Try creating a new profile: https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles#w_start-the-profile-manager-when-firefox-is-closed

Hi TerryN21,

This is great! I love knowing what it will take to get back in the saddle with Firefox! But. I'm just not the technical enthusiast I wish I were, and I'm thinking "What?" by the third step. It is going to be so much easier for me to make friends with Chrome and save myself the anguish of resurrecting Firefox!

I appreciate your reply, and wish you lived next door!

                                                                                              -- Jim D

Addendum: After a day of walking around the solution, I sat down and actually applied it. I followed the instructions, which is hard for me, and the problem disappeared, just like that (snaps fingers). Thanks, TerryN21! Perfect reply/fix to my problem! -- Jim D.

Make sure you install Firefox properly and that you do not run Firefox from within the DMG (Disk Image) file.

Open the Firefox Disk Image file and drag the Firefox application to the Applications folder on your hard drive. You shouldn't double-click the Firefox application to run it from the Disk Image, but instead drag it out of the DMG folder.

• https://support.mozilla.org/en-US/kb/install-firefox-mac

Since I could not find how to start a new thread I will post here. I should have abandoned Firefox many years ago, when my bookmarks, favourites etc. were destroyed by a new update, but back then I found a way to revert to the OLD Firefox and to keep on using Mozilla browser. That was wrong thing to do. This year, already some weeks ago a new update destroyed or deleted all my bookmarks, all my favourites and the "favorite buttons". No matter how hard I tried I could not restore them and was only able to restore some old versions. Therefore for the past couple months I no longer use FF as my main browse3r and I don't use it almost at all. I am posting this on a browser that is okay, not perfect, but okay, which is Microsoft Edge. I am shocked the way Mozilla treated its long time customers and reduced Firefox usage audience from 88% to measly 3% or less. They must have really good reason for that, either be suicidal or masochist or both. Adios Firefox! I am going to add Opera to my portfolio now in addition to Microsoft Edge and Vivaldi and a very occasionally used Google Chrome. But never Firefox ever again.