*SPOILERS*
During the fight that takes place before you obtain Auriels bow where the player fights a small number of waves of frozen Falmer and Chaurus' there is a bug while playing as a Vampire Lord and using the choke ability that is unlocked through the perk tree. While using this ability on one of the frozen creatures and they die (by exploding into pieces of frozen body parts) the game instantly crashes, I did this 3 times in a row having to restart my Xbox each time as the explosion from the choking ability froze the game as one of the creatures died.

Another bug that I discovered is during the side quest where you obtain the two rings that enhance the vampire lord ability through increased magicka or health the game got extremely laggy, especially when getting the health boost ring as there was a lot of Falmer around and also there was a massive stream of water through the middle of the area which doesn't help towards performance. I experienced the most lag as soon as I killed a Falmer making the game slow down up to a point that I thought the game had frozen, but a second or two later it would pick back up and then lag as soon as another Falmer died.

If anyone goes up to the point that I explained in the first paragraph I strongly recommend not using the choke ability for the vampire lord.