Places Maintenance {web link} Allows to run Maintenance tasks on the database that drives Places, the bookmarks and history module behind Firefox.

Open the Add-ons Manager. Locate the add-on and press the Options button. Then follow the directions.

Look on your desktop. Do you see a folder called; Old Firefox?

https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible

Does that happen when the iCloud Bookmarks extension is disabled? You're not using Sync along with that iCloud Bookmarks extension, are you?

I don't even have iCloud Bookmarks installed on my PC. for the last 2-weeks Any new folders I have been creating and any new bookmarks I put in that folder only remain in the Bookmarks folder for a day or 2 then the folder and all the files just dissapear.

CMaster said

I don't even have iCloud Bookmarks installed on my PC.

Your system details show the extensions that you have installed, one of
them is  : iCloud Bookmarks 1.4.24 Maybe you forgot you even had it  ?

I have no idea where it is or how to use it, I can't even find it

Also I am talking about Bookmarks dissapearing on my Windows 10 pc not my ipad, so I don't understand what iCloud Bookmarks has to do with anything. But any suggestions you have that resolve the issue would be great.

CMaster said

I have no idea where it is or how to use it, I can't even find it

You'll find it here :

3-bar menu (or 'Tools') => Add-ons => Extensions.

Discovered Hidden Add-on On Firefox. How To Check Yours https://support.mozilla.org/en-US/forums/support-forum-contributors/711335

Type chrome://mozapps/content/extensions/extensions.xul?<enter> in the address bar.

CMaster said

Also I am talking about Bookmarks dissapearing on my Windows 10 pc not my ipad, so I don't understand what iCloud Bookmarks has to do with anything. But any suggestions you have that resolve the issue would be great.

As you apparantly haven't intentionally installed the add-on iCloud Bookmarks : once you've found it, would you please just disable / remove it and see if that will solve the problem  ?

I notice that your System Details list shows that you have a lot of YouTube extensions, some enabled and some disabled. If you aren't using them or if they may have stopped working in YouTube since YT has made some changes recently then best would be to uninstall (remove) these extensions to cleanup the list.

Note that current Firefox releases have a button on the about:support page to verify the places.sqlite database integrity.

If you use Sync then best is to disconnect Sync while performing maintenance/repair efforts to files in the Firefox profile folder.