Okay, so let me begin by giving a scenario that often happens.
I start by running Blockland and easily get to the main menu screen as it is supposed to do, and nothing is out of order UNTIL I do some sort of process that causes the game to crash, this is usually when I query the server list or am loading a game with a moderate to high level of Add-Ons, which generally means a lot of activity and data transfer.
I switched to a Macbook Pro and installed a Windows 7 partition on the side that runs Blockland. Currently, I have 86.2/185 GB available on this partition. However, this should be plenty of room to run Blockland. What I'm worried about, is if there is some kind of memory allocation issue. For instance, to all Minecraft users, at some point, the game may run out of memory, and the game may have to be restarted entirely in order to continue playing. Does Blockland have some sort of cap on the amount of local data I use on my computer? I never had this problem with any previous computers, and I was able to host about five servers with a large amount of Add-Ons before this problem even came up on this installation.
Also, could having too many processes running at the same time be disrupting this?