Dennis is right about your wiring. You should not wire from right to left like you did from your case output to the DBL converter, and from the DBL converter to the Write. You output of case structures and loops should be on the right side. Inputs on the left, outputs on the right. It is OK to occasionally have inputs/outputs on the top and bottom, You should not hide wires under other objects, like your error wire being behind the case. You don't need to make your case structure so huge, shrink it down to make your wiring easier. Don't make unnecessary wire bends. Straighten some of them out.
Also, use shift registers for the error and task wires when using a loop. This will propogate the information from one loop iteration to the next. If there is an error in one loop iteration, it gets lost on the next iteration because the error in on the left side input is "no error". A shift register will force the error out from one iteration to be the error in on the next iteration.
Put a small Wait(ms) delay in all loops to prevent hogging of the CPU. Look at my modification to your vi.
