Nothing obvious. I think it's time to take a pair of hedge trimmers to your add-ons folder. I advise starting with any client mods that mess with the interface or GUIs, since it looked like it happened just as it was trying to bring up the loading screen.
The only mod I have that messes with it is GUI Plus, and before I installed it the game would still crash.
My blockland crashes when im goin to "Start a game" > "Custom" > "Select" > (Selecting addons) > "Select" > (Setting server stuff) > "Launch game". When its created a server and starts loading addons, some where it crashes!
Then you have some stuff trolling about. Look at the loving console and SEE what addon is causing you to crash.
Delete System_GuiPlus.zipIt causes the crash
Nonsense, guiplus doesn't cause crashes. Maybe you should post your console.log with guiplus installed so we can figure out which add-on conflicts with it and actually causes the crash
Now, every single time I try to launch a server the game crashes.