Return to the previous room and defeat all of the enemies in order to remove the barriers blocking the exit of the castle. (linkshideaway.com)
You also have the option to flee, which would be very helpful if the game didn't block your exit most of the time!. (gamergeddon.com)
It is shameful that an African American attorney general would attempt to block the exits from failing schools in the name of justice. (californiapolicycenter.org)