If you have an invalid or old entry in your /etc/fstab file, the system will not boot because it's waiting for that file - or for you to tell it what to do.
At this prompt, you could have pressed "S" to skip that entry and continue booting or "M" to drop to a shell to fix the problem yourself.
(There is a bug open to replace [SM] with explanatory text)
This is the expected behaviour.
If you have an invalid or old entry in your /etc/fstab file, the system will not boot because it's waiting for that file - or for you to tell it what to do.
At this prompt, you could have pressed "S" to skip that entry and continue booting or "M" to drop to a shell to fix the problem yourself.
(There is a bug open to replace [SM] with explanatory text)