The dialogue box also said me that:
We're Sorryand a check box behind a line, which says:
Firefox had a problem and crashed. We'll try to restore your tabs and windows when it restarts.
Tell Mozilla about this crash so they can fix it.I mark the check box and click on 'Restart Firefox' button at the right bottom. All of my tabs restore successfully when Firefox restart. Thank you Firefox, I am happy with you since 2004.