Subject says it all. It was there last reset, and now is not. The one that ports you down from the tower is still present, however.
On a similar topic. The door to this tower is opened by the Wyrm Watcher key from the outside, and can be locked by this same key. From the inside however, there is no means of locking this door.
The exit from the forest towards mistlock is also missing.
The transitions are there.
The transition has now been corrected, yes. However, a new bug has popped up now.
When inside the tower, clicking the doorway transition to go out. Rather than appearing directly outside of the tower, you now appear all the way at the bottom of the rockpile, on the transition you take to climb up.
Fixed.