Looks like my perfect knight achievement is glitched. I just finished all the challenges and have 99% completed. I got all the riddler challenges and at the main menu it showed 239/240. I load up, run the last trophy, hear riddler complaining how i collected all the pieces and nothing. No achievement no nothing. Earlier in the game my 10% of riddler challenges glitched and I didnt get it either. I dont think it matters as the achievement calls for all upgrades, riddles, and gold on all challenges. 
 
Anyone have a suggestion besides play through all this shit again?

What version of the game do you have? i've never heard of this glitching before.

Glitched achievements/trophies are the fucking worst. Unfortunately there's not really any solution.

Standard xbox 360 version. Not GOTY. Oh wait i see the problem now. Its one of those gamestop exclusive DLC ones. j/k i know that doesnt matter.

Did you get the final Arkham memorie thingy?

" Standard xbox 360 version. Not GOTY. Oh wait i see the problem now. Its one of those gamestop exclusive DLC ones. j/k i know that doesnt matter. "