In the North American version of Pandora's Tower (and possibly others) there is a glitch that when you try and enter the 11th or 12th tower a second time, the game will crash. Many people have many workarounds, but many of them seem to slowly not work since the nature of the glitch seems to change.
The best way to work around this glitch is to first visit Sheerdrop Spire. After visiting turn around and head back to the Observatory. After reaching the observatory turn around and run to the ledge to give the game time to load and stop moving. Once Aeron's animation has ceased other than the cape slightly blowing in the wind, open the tower select menu and select Dusk Tower. This will still crash about 5% of the time, but most of the time it will let you go to Dusk Tower. Then go to Dawn Tower from Dusk Tower and it will load like normal.
Workaround discovered by Eternalclaw