I'm sorry to hear about this. Firefox doesn't keep backups of history, so there isn't a quick solution to restoring what was deleted.

I wonder whether Firefox determined that the Places database file -- the file which stores bookmarks and history -- had become corrupted and started a new one. The only way there would be history in a fresh file if it had been restored from data in the Sync cloud (if you use Sync).

In this situation, I think Firefox preserves the "corrupted" file, and it might be possible to still obtain information from it. However, this is hit or miss. Either way, the first step is to see whether you have such a file:

Sometimes the settings file that stores window dimensions becomes corrupted with nonsensical values. You can rename the file and have Firefox rebuild it. Here's how:

Open your current Firefox settings (AKA Firefox profile) folder using either

• "3-bar" menu button > Help > More Troubleshooting Information
• (menu bar) Help > More Troubleshooting Information
• type or paste about:support in the address bar and press Enter

In the first table on the page, on the Profile Folder row, click the "Open Folder" button. This should launch a new window listing various files and folders in Windows File Explorer.

Scroll down and look for places.sqlite.corrupt or places.sqlite-corrupt and if you find one, right-click > Copy, then right-click > Paste on your desktop or somewhere else that there's no danger of Firefox modifying/replacing it.

Did you find anything along those lines?

hello,

sorry for late response.

i found those files and copy-pasted those files on my desktop, as per your suggestions. what to do now?

Could you try using this third party program to list out the history in one of those files:

https://www.nirsoft.net/utils/mozilla_history_view.html

After downloading/installing:

(1) Double-click MozillaHistoryView.exe to start it up

(2) The program might list your currently live places.sqlite file. To read out the file you pasted to your desktop, click the ... button to the right of the file name (this is the first field on the screen for this program).

Note: if you cannot open the file with its original extension (.corrupt or .sqlite-corrupt) you might need to first rename the file to something like places-corrupt.sqlite (making sure the extension is .sqlite) before the program can read its contents.

(3) Uncheck the date range boxes to make sure you see everything.

(4) Click OK and see what the program can extract. Anything?

i did change the extension of the file "places.sqlite.corrupt-shm" (which i copy pasted on my desktop) to "places-corrupt.sqlite" to make the file readable in the program. but i didn't see anything as per your step 4. did i do it correctly?