Setting a cart manager block down next to an advanced detector rail, if I open the gui by right-clicking the block, I am able to manually move things in and out of the inventory, but if I click on any of the arrows to change the direction in which the cart manager will interact with carts, or if I click on any of the color-changer icons for any side of the cart manager block, it immediately crashes minecraft out of single-player or SMP.

I need the crash log.

Closing as no log was provided.