Is there even a dev in this community ?! so ridiculous

Hi,

The people who answer questions here, for the most part, are other users volunteering their time (like me), not Mozilla employees or Firefox developers. If you want to leave feedback for Firefox developers, you can go to the Firefox Help menu and select Submit Feedback... or use this link. Your feedback gets collected by a team of people who read it and gather data about the most common issues.

You can also file a bug report or feature request. See File a bug report or feature request for Mozilla products for details.

You may have corrupt sessionstore [v56] sessionstore.jsonlz4 file(s). Delete all sessionstore* files and the sessionstore-backups folder.

Don't delete the files if you need to rescue any data from them, just move them out of the profile folder to some location where Firefox doesn't look for them. You can try to read out their contents using this tool: https://www.jeffersonscher.com/res/scrounger.html

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

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

Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder

Linux: Under the page logo on the left side, you will see Application Basics. Under this find Profile Directory. To its right press the button Open Directory.

Locate the above file. Then rename or delete it. Restart Firefox.