I am an ACTIVE user of browsers, at any given time I have at least 10 windows open with multiple tabs in each of them, so much that I also use Private/Incognito windows on a daily basis.
Now you have for the second time in a month done an update in the background which suddenly FORCES me to restart Firefox because all new tabs just say "Firefox has been updated, you need to restart" and then I have a Restart button to click without any other option.
This means that you FORCE me to also close ALL my Private/Incognito tabs, that you have of course NO intentions of opening again automatically for me, since hey, they are Private and shouldn't be stored.
But this is really getting on my nerves now and if it happens again I will be forced to ditch Firefox again, would be such a shame.
Either stop updating that causes you(me) not to be able to handle a new tab,
or do as previously, give me info of the update and allow me to click update in the menu as it has been the way for the last LOOOOONG time.
I do wonder what the rationale is for forcing people to restart - regardless of what they may be currently up to? I find this very annoying but beyond that I can see cases where it is downright harmful. Imagine someone urgently researching medical information and trying to find the way to the nearest A&E. To not give the user control over whether they want to continue using their browse is the worst design decision I have seen in Firefox ever, by a wide margin.