That's very odd... I tested out the errors and it is weird. It doesn't error out when I have two clients open for some reason. I can open a menu and do things normally (like leave the map) but once I log off on one client the other one freezes. For some reason the ABS controller is basically glitching out because the client is saving the enemy in a spot that isn't it's default location.
I will bet money that the reason the client is erroring out and the server is crashing is either because A. the freeze when the menus are called because the menu clashes with the online system (because online gameplay is way different from offline and calling a menu is basically like pausing a heartbeat for a long time) or B. faulty saving... the server may be saving a negative (or dividing by zero). once the menu is up the player may be disconnected while still being connected.
No matter which (if any) of these it is the blatantly obvious is the BABS controller (and it's just that... I tested) is incompatible with menus, shops, its own hotkey script call, and any scene that freezes the game. The only way to basically solve that problem is to make a custom scene using pictures that doesn't freeze the game. The hotkey scene and such are annoying to re-make but noone said it'd be easy.
The biggest annoyance is the fact that the chatbox doesn't wory and the mouse system barely works (both are glitchy when the BABS controller is installed and works perfect without it.) Even with all the bugs is by far one of Blizz's most impressive creation. The customization and finesse involved in its birth is awe-inspiring to say the least. I've had a blast playing around with the system... such a blast that I forgot to eat for 2 days just staring at one map tinkering. I haven't felt this curious since christmas as a child.