There are many, many reasons for the "Can't connect to map server." error message, so I'll give you a few ideas on how to fix it.
For one thing, if that "Can't connect" message comes up, do not press yes, because you'll just sit there for hours without it doing anything. The thing I usually do when I get that message is close the game, then reopen it and try again.
I've not had the problem of this happening continuously. If it's only been happening for a short while, the server may be full or have recently crashed. Keep trying.
If it's been happening for days or weeks, then the best thing you could do is un and reinstall FeralHeart.
It could also be a problem of bad internet connection. If you have wireless internet connection, try moving closer to the router.
Hope one of these ideas helps.