[Alan Anderson]

The FRAME PERIMETER is defined by the extent of the robot frame, excepting minor fastener protrusions, within the BUMPER ZONE. Such protrusions in the BUMPER ZONE are exempt from the rule prohibiting any part of the robot from extending outside the FRAME PERIMETER. Protrusions outside the bumper zone are not exempt from the rule. Your design has bolt heads outside the FRAME PERIMETER and thus breaks the rule.

To fix it quickly, make your FRAME PERIMETER bigger so it encompasses all the protrusions. Add a thin strip of some solid material to the outside of your robot where the bumper will fasten.