Hi,
I just got the GOTY for xmas and ran into this same problem. I had saved the game just before claiming the castle, so I could repeat the crash. I felt the cause was similar to the previous reply as the behavior was like a similar problem I had with Oblivion on another PC. The load screen between levels freezes and sound goes into a loop.
I played with graphics on Ultra (Nvidia 1070) I went through each setting and narrowed my problem to the settings for Water Quality. I lowered to High and was able to claim with no further freezes.
Sort of makes sense for me since there is a lot of water on this level, especially with little waterfalls, etc. Hope his helps others.
