First let's check your system; Perform a System File Check to fix corrupted system files

Win 7, 8, 10, Vista: https://support.microsoft.com/en-us/kb/929833 Win XP: https://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/system_file_checker.mspx?mfr=true

Wiki - Windows 10 System File Check http://answers.microsoft.com/en-us/windows/wiki/windows_10-update/system-file-check-sfc-scan-and-repair-system-files/bc609315-da1f-4775-812c-695b60477a93

If you have sync, and there is a problem anywhere, Shut Down Sync Immediately On All Devices to prevent the problem from spreading. Type https://accounts.firefox.com/settings<enter> in the address box. Once the problem is fixed, perform the same repair on all computers/profiles before using sync again.

[v57+] Places Maintenance is built into Firefox.

Type about:support<enter> in the address box.

You will find Places Database near the bottom. Press the Verify Integrity button.

If any errors are reported: https://support.mozilla.org/en-US/kb/fix-bookmarks-and-history-will-not-be-functional

The places.sqlite and favicons.sqlite files contains your History and Bookmarks. And it looks like they are corrupted.

Type about:support<enter> in the address box.

Under the page logo on the left side, you will see Application Basics. Under this find Profile Folder. To its right press the button Show Folder. This will open your file browser to the current Firefox profile. Now Close Firefox.

Locate the above files. Then rename or delete them. Restart Firefox. The browser should then create a new place.sqlite and recover your bookmarks from the backup files.

Note: Your history is not backed up and will be lost.

Creating a new places file will defeat the purpose. I want to keep the old history. Checking the integrity gave a lot of errors. ask: checkIntegrity - Unable to fix corruption, places.sqlite will be replaced on next startup > Task: invalidateCaches - The task queue was cleared by an error in another task. > Task: checkCoherence - The task queue was cleared by an error in another task. > Task: expire - The task queue was cleared by an error in another task. > Task: originFrecencyStats - The task queue was cleared by an error in another task. > Task: vacuum - The task queue was cleared by an error in another task. > Task: stats - The task queue was cleared by an error in another task. > Task: _refreshUI - The task queue was cleared by an error in another task.

How to uncorrupt it?

I don't know if there is a way to save the data.

I called for more help.

Have you tried deleting the places.sqlite before?

Let's at least try to save your bookmarks.

Open the Bookmarks Manager; Press the Alt or F10 key to bring up the toolbar, and select Bookmarks. Hot key is <Control> (Mac=<Command>) <Shift> B. Firefox 84+ <Control> (Mac=<Command>) <Shift> O.

Once the window is open, at the top of the page, press the button labeled Import and Backup. Select Export Bookmarks To HTML, and follow the prompts and save it to a HTML file. Copy the file to another computer/profile. Repeat the instructions above, BUT select Import Bookmarks From HTML.

https://support.mozilla.org/en-US/kb/restore-bookmarks-from-backup-or-move-them

https://support.mozilla.org/en-US/kb/recover-lost-or-missing-bookmarks

Mozilla search: Import {web link}

Once again, if I delete the places file, it'll defeat the purpose. The whole idea is that I want to keep the history since 2014. Here's what happens: whenever Firefox is closed, it creates a new places file. The old places file is renamed to places.SQLite.corrupt and stored in the folder. I then have to delete the new places file and rename the corrupt file to remove the .corrupt part and viola, it's back to normal. I'm not worried about data getting lost as it never gets lost, I just don't want to rename the file each time Firefox closes.

Okay, let's do this. Next time the file is corrupted, do not rename it. Next time you open Firefox, does this happen again?

I am hoping someone will respond that knows how to save the file.

Just tested it and no, the new places files does not corrupt after restart, only the old one that is 75MBs gets corrupted. New one generated is only 5MBs, and remains uncorrupted. But I don't want a new places file. I want to keep using the old one. I may be wrong here, but I think after version 80 something, Firefox upgraded the old profile to meet the requirements of the new build and I think something happened there. I never turn off my PC, so I only noticed this issue a year or so ago when I closed Firefox. Generally my computer stays on for years on end and browsers stay open

Please wait for someone that can help save the file.