What does this code I'm getting on my 99 Audi A6 mean? (Cylinder 1 Fuel Injector

Circuit - Open circuit)? When I plug the little computer thing into my 99 Audi A6 2.8L, I'm getting code P1237-- Cylinder #1 Fuel Injector Circuit - Open Circuit.

What does that mean is wrong with my engine? What can I do about it? Is it a simple fix or should I go to the mechanic, and how much will it cost to fix?

Thanks in advance!