ID: -108 is the message I get when the error pops up, that Illustrator does not have enough memory to complete the task.
What I am doing is creating an offset path on an object so that I can create a die cut for a sticker. After creating the offset path, I then need to merge in pathfinder (unite). While it's merging, it takes sooooo long - like minutes long. Then, after so much time, I get the error.