***GLITCH*** - Gulum-Ei disappears after leaving the tavern and the map does not properly pinpoint his location.
***REASON*** - If you do not get outside quickly enough, Gulum-Ei somehow climbs over the main wall, jumps, gets stuck, and cannot be seen. (I saw him glitching up the wall.)
***SOLUTION*** - Get outside before Gulum-Ei glitches all of the way up the wall. If you are able to see him, he will slide back down and proceed normally. If he glitches over the wall, re-load your previous auto-save.
This worked for me, but there may be other ways to solve this glitch. --- Do not read this sig.
Lost him in the warehouse. Followed him to the warehouse but all I got was a location indicator. Went into the grotto and it updated my quest to confront him, but still just have an indicator somewhere in the back wall.