Arduino Uno + SeeedStudio CANBus Shield v1.2 -- Connection of shield ruins code

Dear All I am an arduino novice, and it's my first time using the seed studio CAN BUS shield v1.2

I have connected the board to begin adding CAN BUS functionality to my code. Upon adding the shield without making any modifications to the code, the program no longer runs after compiling. I have connected to pins that all appear "free" according to the shield diagram.

Any advice?

Could you be so kind and provide some links to the documentation and diagrams? Otherwise you are making us chase the documents instead of looking at the issue itself.