It sounds like your version of Firefox keeps getting downgraded to an older version for some reason. That means that Firefox's downgrade protection is kicking in.

If you use a profile on a newer version of Firefox, it's locked to that version or higher. If you then try to update that profile with an older version of Firefox, it will not allow you to and will force you to make a new profile.

The reason it does this is in case something changes about how your data is stored.

For example, if Firefox 72 stored your bookmarks in a certain format and Firefox 73 stores in a new format. When updating from 72 to 73, Firefox can convert your old format to the new format. But it can't do the opposite from the new format to the old format. So trying to run that profile in an old version of Firefox could lead Firefox to think the data is corrupt and erase it to start over.

To fix this problem, you need to find out why your Firefox version keeps getting reverted back to a previous version.

I common issue, mostly on organization computers, is that the IT department has set a certain version of Firefox to install when you turn on the computer. But if they haven't disabled updates on Firefox, it will be updated while you use Firefox. Then, when you start the computer again, the updated version will be replaced with the version that the IT department has on their software management system.

Do you possibly have other Firefox versions installed like a beta version that you accidentally start and that uses the same profile ?

Firefox may not complain if you try to start Firefox with a profile that has been used by an older Firefox version.

When this happens again the you can check the compatibility.ini file in the profile folder. This file stores settings like the last Firefox version that has used the profile and its file path.

The Firefox profile folder is in a hidden location in AppData\Roaming.

• C:\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles\<profile>\

Thanks for the responses I have created a ticket with our IT team. I need to use 2 different browsers for my work with customers (theirs and mine). Btw - the worst part of this is trying to replace my bookmarks. Firefox has easily the worst bookmarks manager on the planet. Just finding the bookmarks tool to import html file - is a hidden click - requires a trip to youtube.... Fix that and I would be happy to upgrade :-)

I've been updating Firefox all along, but I never synced because I used Firefox only on one device. But a month or two ago, I got a new version of Firefox and it asked to create a Profile, which I'm not sure I'd ever done before in more than 10 years of using Firefox. Now all of my old bookmarks and extensions are gone and I have absolutely no idea where they might be.

Hi jayfest!

A Firefox profile is different from a Firefox Account. A Firefox Account allows you to use Firefox Sync. Your Firefox profile is simply the folder on your computer where your data (bookmarks, etc) is stored.

If you created a new Firefox profile, you won't see any of your past data (bookmarks, etc) because a new Firefox profile always starts out blank, with just some default stuff.

What is likely happening in your case is that you now have two Firefox profile folders on your computer (your original and the one that you created), but the new one that you created is now set as the default profile, meaning that Firefox automatically loads that profile each time.

This is usually an easy thing to fix. For steps to fix the problem, take a look at the Determine if Firefox has created a new profile section of the Recover lost or missing Bookmarks article.

Hope this helps.

Why do we HAVE to create a new profile?

Makes no sense if it is going to remove or rename and lose the data from the old profile. Seems a stupid development. Just keep the original. No one has profiles they know about do they?