I am able to get into it just fine. However, I have noticed that sometimes FH just doesn't like the character you are on. For example, when I'm on one of my wolves, and Fluorite goes on a crashing spree, it almost never lets me back on that character until several hours later.
I would recommend that you try a different character altogether to get into Ascension Isle and see if that works? If not, I'm not sure what to tell you.