Enigma data pack in the Royal Hotel's ballroom is inaccessible
Solution 1:
As is mentioned in this walktrough:
Inside the West Tower Ballroom, in the Royal Hotel. You must glide over to a wooden platform in the center of the room. Hack the keypad, and it will reveal the datapack.
The link to the video the explicit process on how to get the pack
NOTE: People have reported that this was/is a bug that people have experienced. If this is the case, I suggest loading an older save file (I can't remember if that is possible)