Have you tried looking through your history?

history is present but it`s a lot of work to try to find every tab I had open there were over 20 I think in each window Is there another way i can restore those tabs back? And what caused that loss of information? thank you

Hello Serban_md,

Thank you for contacting Mozilla Support. I'm sorry that you've lost you're previous session. Hopefully these suggestions get you back up and running, but as feer56 suggested you can reopen these tabs by opening your History.

Give these steps a try:

• On the menu bar, click the History menu and select Restore Previous Session.

If this option is not available try:

• Enter about:sessionrestore in the Location Bar (address bar) to force the Restore Session page to appear.

If neither of these options display you're previous tabs, you'll need to restore from the History.

I hope this solves your issue.

Cheers, Patrick

You can also check for Recently Closed Tabs/Windows

Use "Firefox > Exit" (Windows: Firefox/File > Exit; Mac: Firefox > Quit Firefox; Linux: Firefox/File > Quit) to close Firefox if you are currently doing that by clicking the close X on the Firefox title bar.
Wait a bit longer (45 seconds) to give Firefox more time to close properly before shutting down the computer.