11" is 29%, in the expected average range for monos. 12.5" is 33%, also in range. Different hulls will have different CG requirements, and different speeds can require different CG values. Start with what the manufacturer recommends.
It is not possible to say how the hull should sit in the water while static. Most monos will be a bit bow-high but it depends on the design. Put your model together with a CG 11" ahead of the transom and you should be very close to perfect.
ERROR 604 - Caller's Buffer Is Too Small
1. Ensure that your port is not configured to a low speed
2. If you are still having problems, contact your counselor