Is there an error message? There is nothing wrong with Cape, but if you're getting messages such as "Can't connect to map server. Retry?" or "Bad Token", then you're probably lagging. There could be too many people in Cape or you have a bad internet connection.
If this has been happening for a long time, you might be missing the Cape of Distant Worlds map, in which case you do need to uninstall and reinstall FeralHeart. Though that's unlikely, seeing as you still have the option to actually go through the portal. It's more likely to be a lag problem.