Do you want to save your History as a text file? Then Firefox doesn't have a way to export the History as a text file. The JSON backups in the bookmark-backups folder only store the bookmarks and not the history. but you can visit this site and try to solve your problem http://www.nirsoft.net/utils/mozilla_history_view.html

Hi German, sorry to hear about this problem.

Your Firefox reported itself as version 72 (Beta or Developer)

'Is that the correct version? Everything that follows assumes you haven't accidentally changed from a regular release to an early release in your latest update. If you think you might have changed release and you prefer the regular release (Firefox 71), see whether it is available under a different icon or re-install it.

If you haven't already, could you close out of Firefox and do a normal Windows shutdown and restart to complete any pending updates and release any file locks.

If Firefox again starts up without your data, could you check whether your stuff is available in a different profile, as follows:

Profile Manager Page

Inside Firefox, type or paste about:profiles in the address bar and press Enter/Return to load it.

This page should list at least one profile and could list many. (Each profile has two folders and one or more buttons. Do not use any Remove buttons!)

The profile that Firefox is currently using will have this:

This is the profile in use and it cannot be deleted.

Do you have another profile named default or default-longnumber listed on this page? If so, you can check whether it is the one you were using recently by clicking its Launch profile in new browser button.

If it isn't what you want, simply close that new window.

If it IS what you want, back on the about:profiles page, click the Set as default profile button for that profile so Firefox uses it automatically at the next startup.

Any progress so far, or do we need to keep looking for your data in some other places?