If ye' don't mind me questionin', is there a folder located in yer Local Disk (C:) > FeralHeart > Media > Terrains named Packs (assumin' this is yer map's name)? I was for sure the second quote would be of use. How problematic..
There should be a folder in the said location (Terrains) named after yer map. Since yer terrain (and/or mask) files are unable to be located by yer computer software, I have a haunch that said files either are nonexistent or are misplaced. They should be located inside yer map's name folder, labelled as Packsterrain.png and/or Packsmask.png. Are ye' sure ye' have the correspondin' suggestion precise?
If nein, take a look at this tutorial to see where ye' may have faltered:
>>Click here!<< (http://www.feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&topic=37343.0)
It would be a good idea to make a new thread if you have a problem like Vespian said before. In this way, more people will look at it and try to answer.
You should probably check your internet connection and if it's low. Sometimes when there is a lot of users playing, a powerful connection may be needed to join the fun in game.
Also, check if any of your security programs are blocking the game. Security programs such as; BitDefender Internet Security, Kaspersky Internet Security, AVG Internet Security may block you from joining and connecting to the server(s).