I see that's quite a strange bug, I was hoping I fixed any weird issues with All-star mode!
Would you be able to tell me what teacher you were playing with? Also were you playing with a modded teacher in your game, with their wordlist enabled? If you had a modded teacher with a custom wordlist, try to see if that teacher's wordlist works fine on its own on a lower difficulty.
Also can you play with Non-Touhou words just fine on a normal difficulty?
It sounds like your game failed to find the Non-Touhou wordlist or there was an issue with parsing words that should have been available which seems very strange.