Constant crashing when commencing the "Alexander - The Arm of the Father" raid

Every other instance in the entire game works perfectly fine when the game loads it but it seems that the game crashes every time I commence this duty. The rest of Alexander has no such problems. It has been happening for about a month now. Once in a blue moon the instance actually loads and works but about 95% of the time the game crashes upon loading it.

This problem arrived out of nowhere as this instance has worked for me since it was launched. For clarification I am talking about the Normal version, not the Savage version, and I have tried loading the fight in with both DX9 and 11 clients. I have also re-installed the game once but that has not helped.