Bug/Glitch:
For a part of the quest, you have to shadow Gulum-Ei and stalk him to the EETC (East Empire Trading Company) warehouse on the docks underneath and beside of solitude. The problem is that he sometimes completely disappears from the game and you can then not follow him and complete the quest. The compass marker points to the warehouse, but once inside it points nowhere and he is nowhere to be found. I used the spell named Clairvoyance in the warehouse but it said there is no clear path. I looked at YouTube guides and they show Gulum-Ei should be there and you follow him into a cave where you then kill bandits and then confront him.
Possible fix:
This glitch happened to a lot of 360 users and have tried multiple ways of fixing this glitch (even trying to fall underneath the map and finding Gulum-Ei in the river next to Solitude (I tried this method with no success)). This glitch seems to happen mostly when Gulum-Ei exits Solitude through the main gates or when he enters the EETC main door. After that he vanishes from the game and you can not complete the mission. I have tried all possible ways of restarting the area to get Gulum-Ei back, but none have been successful.
Thanks