sometime its happen due to the malware of the website. how to the resolve , 1 you can going to the tool -> setting --> HOME and check and change New Windows and Tabs default 2 but easy way uninstall and reinstall browser

You can for for issues after updating. *https://support.mozilla.org/en-US/kb/recover-user-data-missing-after-firefox-update See also: *https://support.mozilla.org/en-US/kb/how-to-set-the-home-page *https://support.mozilla.org/en-US/kb/how-to-fix-preferences-wont-save If this is about reopening tabs from the previous session then you can possibly try to restore a recent upgrade.jsonlz4 file in the sessionstore-backups folder in the Firefox profile folder. ----- You will normally find these files in the sessionstore-backups folder: *previous.jsonlz4 (cleanBackup: copy of sessionstore.jsonlz4 from previous session that was loaded successfully) *recovery.jsonlz4 (latest version of sessionstore.jsonlz4 written during runtime) *recovery.baklz4 (previous version of sessionstore.jsonlz4 written during runtime) *upgrade.jsonlz4-<build_id> (backup created during an upgrade of Firefox) You can copy a file from the sessionstore-backups folder to the main profile and rename the file to sessionstore.jsonlz4 to replace the current file with Firefox closed. *make sure to backup the current sessionstore.jsonlz4 You can look at this tool to inspect a compressed jsonlz4 sessionstore file. *https://www.jeffersonscher.com/res/scrounger.html You can use the button on the "Help -> More Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the <b>about:profiles</b> page (Root directory). *Help -> More Troubleshooting Information -> Profile Folder/Directory:<br>Windows: Open Folder; Linux: Open Directory; Mac: Show in Finder *https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data