Hi misersclub, there are live humans here, but obviously some delays in answering questions.

Do you get a particular error message when you try to load your profile?

Does this article help at all: How to run Firefox when your profile is missing or inaccessible?

1) Windows 10 upgrade, it created a new Windows local user, predictably the Firefox data (bookmarks) needed did not come over since the old windows user was on a network domain where I am no longer a member 2) Tried copy and paste the Firefox profile from old Windows domain user into the new Windows local user, that corrupted the Firefox profile, deleted it, and Firefox would not recreate. 4) Since my outreach, managed a fresh install that has a new Firefox profile, without the needed bookmarks, back to where I started.

Okay. You still have a copy of the old profile? If you have a recent bookmark backup there, you can restore that.

This will replace any newly added bookmarks in your currently live profile.

(1) Make sure Windows is set to show hidden files and folders

https://support.microsoft.com/en-us/help/14201/windows-show-hidden-files

(2) Find your old profile folder, and its bookmarkbackups subfolder

C:\Users\old-username\AppData\Roaming\Mozilla\Firefox\Profiles\old.folder\bookmarkbackups

(3) (Optional) Copy the latest/largest file to a more convenient location, such as the root of C drive.

Each file name should have the creation date and number of items (folders + bookmarks) coded into its name for reference.

right-click the file > Copy

then open the more convenient folder and

right-click a blank area > Paste

(4) In Firefox, use the Library window to Restore that file. You'll need to use the "Choose File..." options to point Firefox to the more convenient folder, or the old profile folder if you skipped step 3.

See: Restore bookmarks from backup or move them to another computer

Success?

Hmm, actually in Step #2, your profile folder sounds as though it is somewhere else. It still should have a bookmarkbackups subfolder in it.

YEEEHAAA!!!! That worked perfectly. Couldn't have done it without you. Thank you so much for the advice, and on the weekend. You rock!