This same thing happens to me now, I got into the Cadash Taig, and then all of a sudden the game crashed and won't load any saves. I tried repairing the game, and it didn't work. Then I deleted the character and made a new one and it seems every time I make it to the taig, the game crashes and then won't let me load any of the previous saves for that character. The other DLCs work, and I can load saves in the base game and awakening but not witch hunt.
did you install the 4 gigabyte patch?
if you are on steam, follow this for the patch
https://steamcommunity.com/sharedfiles/filedetails/?id=233222451
