Eeh, i think i have the reason for this.
Most likely you have been playing on the old Evocity map correct?
Recently the Staff team has released a new map called Paralake city V1 [ Version 2 will be released somewhere soon i believe], however this map has such a huge size + all the players + all the npc's and the rest of the content thats included that it takes your operating system a bit of time to load the map, and this can take up quite long [5-10 minutes for example as far as i've heard , crazy].
1. I think the possible reasons are that you could have a windows 32 bit operating system and so i suggest upgrading to 64 if you haven't already.
2. You have a 64 bit operating system [ like windows 7 64 bit for example] but you don't have enough RAM in your computer, if thats the case [ i believe you need 6gb+ RAM so get a smooth and quick join-in as far as i've heard from people. If thats the case, and you desperatly want to join the server again then i suggest upgrading your pc with 6gb+ ram memory [ 6gb - 8gb - 16gb - 32gb etc. however 16 and 32gb is really unnecessary so don't worry about those].
I hope it helped a bit =).
Kind regards: Shortyzz