After a crash, when Firefox is restored, I get many blank pages opening, in addition to the correct page. It takes a while to close them all.
The new version of Firefox also seems to be crashing more than the old.
Opaite Mbohovái (1)
Set the pref browser.sessionstore.max_resumed_crashes to 0 on the about:config page to get the about:sessionrestore page immediately with the first restart after a crash has occurred or the Task Manager was used to close Firefox.
That will allow you to deselect the tab(s) that you do not want to reopen, but will allow to reopen the other tabs.
See:
To open the about:config page, type about:config in the location (address) bar and press the "Enter" key, just like you type the url of a website to open a website.
If you see a warning then you can confirm that you want to access that page.