First, make sure that 'Show your windows and tabs from last time' is still checked.

You may have corrupt sessionstore 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

Thanks for that. However: Locate the above file. Then rename or delete it. I don't understand which file I should locate and delete. Could you help please?

rafikiphoto said

I have 'Show your windows and tabs from last time' set but when Quantum 57 restarts nothing is restored. Any clues?

Did you look at your Privacy&Security to see if any of the history options were not checked because I know by default clean install FF does have some of those checked marked so when you close FF they get wiped out. So you need to go there and look to see if anything is changed there.

rafikiphoto said

I don't understand which file I should locate and delete. Could you help please?

FredMcD said

Delete all sessionstore* files and the sessionstore-backups folder.

Hi rafikiphoto, there are several possible reasons for this. Some of the more common issues are:

(1) Firefox is set to clear history when it closes. Since history includes your tabs, there they go. (This is what WestEnd suggested checking.)

You can check that on the Options/Preferences page:

• Windows: "3-bar" menu button (or Tools menu) > Options
• Mac: "3-bar" menu button (or Firefox menu) > Preferences
• Linux: "3-bar" menu button (or Edit menu) > Preferences
• Any system: type or paste about:preferences into the address bar and press Enter/Return to load it

In the left column, click Privacy & Security. Then on the right side, select "Firefox will: Use custom settings for history". Make sure you do NOT have a check mark for "Clear history when Firefox closes".

Or if you do want to clear SOME categories of history, click the Settings button to the right and make sure you do NOT have a check mark for "Browsing & Download History".

(2) Cleaning or other utility software removes Firefox data between sessions.

Programs that can do this include CCleaner and Advanced SystemCare. If you use any programs like that, adjust their settings so they do not remove Firefox sessions (or maybe don't remove any Firefox data).

FredMcD said

rafikiphoto said

I don't understand which file I should locate and delete. Could you help please?

FredMcD said

Delete all sessionstore* files and the sessionstore-backups folder.

Thank you. It was the reference to just a "file" that made me wonder.

Thank you everybody for your kind assistance.