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Firefox 60.0.2 (Mac) repeatedly opens to 'can't restore previous session', but restores after selecting 'restore previous tabs'.

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Since the last update, Firefox almost always opens to a 'can't restore previous', but restores correctly after selecting 'restore previous tabs.' Also occurs with add-on's disabled.

Typically, browser screen flashes for a second on start-up, quickly closes and then reopens with the error message described above.

Only other programs resident are Onedrive, Avast (free version), Malware Bytes (free version).

Since the last update, Firefox almost always opens to a 'can't restore previous', but restores correctly after selecting 'restore previous tabs.' Also occurs with add-on's disabled. Typically, browser screen flashes for a second on start-up, quickly closes and then reopens with the error message described above. Only other programs resident are Onedrive, Avast (free version), Malware Bytes (free version).

All Replies (3)

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Did you want the browser to open with the last session?


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

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

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 file. Then rename or delete it. Restart Firefox.


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

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I took your advise and it worked until I rebooted. I then also installed a Mac OS update. The problem has come back. I will repeat the process.

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Hi, Offidano!

FredMcD said

Did you want the browser to open with the last session? You may have corrupt sessionstore [v56] sessionstore.jsonlz4 file(s). Delete all sessionstore* files and the sessionstore-backups folder. Type about:support<enter> in the address bar. 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 file. Then rename or delete it. Restart Firefox. 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

That is not all that necessary. You can easily fix the problem by downgrading (which usually works) to a older version like 52.0. You can access that page at https://ftp.mozilla.org/pub/firefox/releases/52.0/ and install the MacOS version. Good Luck!