Normally Firefox tries one automatic crash recovery, but sometimes users reduce that to zero to make sure they have the ability to remove a bad tab from the list of restored tabs. To check whether your Firefox has been customized that way:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk.

More info on about:config: Configuration Editor for Firefox. The moderators would like us to remind you that changes made through this back door aren't fully supported and aren't guaranteed to continue working in the future.

(2) In the search box in the page, type or paste browser.sessionstore.max_resumed_crashes and pause while the list is filtered

(3) If the preference doesn't have its default value of 1, click the Reset (left-arching arrow) button at the right end of the row to restore the default value of true

Mine has the 1.

It's been this way for years. :(

The main reason I Force Quit Firefox is that bookmark controls fail to work. I don't see how hitting the button is any more useful than Firefox simply reopening my tabs, without me to hit a button. If there's a problem tab, then that should be a separate option.

Okay, so it sounds like Firefox is doing the normal thing: trying to restore your session automatically but running into a problem and presenting you with the option to either try again or start a new session. This could indicate that there is a bad tab somewhere in your browser, but somehow not bad enough to cause the process to fail a second time. Off the top of my head, I don't have a plan for figuring out which tab is causing the problem.

But since it always works on the second try, you could increase browser.sessionstore.max_resumed_crashes to 2 and see whether that bypasses the problem.

That just makes no sense. It doesn't matter which or how many tabs are open, it fails to restore 100% of the time. It has failed 100% of the time, for several years. I'll try setting it to 2. I'll reply back in a couple of weeks to see if this solves this nonsense bug.

The 'trouble restoring pages' message might just be a false alarm if all tabs restore correctly—likely nothing to worry about!

if not a problem, why is Firefox doing this to us?