That is strange. Has Firefox been creating a new profile for each session? To check on that, try the steps in the first section of the following article: Recover lost or missing Bookmarks.

"Has Firefox been creating a new profile for each session?"

I don't know. How do I check this?

I just reinstalled it. In the Profiles folder there are two folders:

3hb6aolj.default contains 1 file: times.json

and

s89wjjsv.default-release contains--12 folders and 38 files.

Okay, it sounds like you only have one active folder (default-release). Is this under the Roaming path?

C:\Users\<username>\AppData\Roaming\Mozilla\Firefox\Profiles\s89wjjsv.default-release

Can you see Firefox updating that profile as you browse? For example, these files in the sessionstore-backups folder should be updated about every 15 seconds if you are opening a lot of new pages:

• recovery.jsonlz4
• recovery.baklz4

If you check the extensions folder, does it contain the number of extensions you expect?

Okay, it sounds like you only have one active folder (default-release). Is this under the Roaming path?

C:\Users\<username>\AppData\Roaming\Mozilla\Firefox\Profiles\s89wjjsv.default-release

Can you see Firefox updating that profile as you browse? For example, these files in the sessionstore-backups folder should be updated about every 15 seconds if you are opening a lot of new pages:

   recovery.jsonlz4
   recovery.baklz4 

Yes it appears so.

If you check the extensions folder, does it contain the number of extensions you expect? Yes.

I deleted the '3hb6aolj.default' folder and so far I'm not having the same problem.

That's progress. In one of your other threads it was good for 4 days. Let's see how it goes this time. Maybe back up default-release daily?

"Maybe back up default-release daily?" May, but I don't want to have to keep doing that.