u/Hot_Disaster_17

My dad has a ego zero turn mower and has loved using it to mow our yard for awhile. The other week he was mowing and hit a rock and bet one of his blades. We replaced the blades and now we are getting a 509 error code. I think this code relates to having a loose left blade but he tightened the blades significantly and the code persists. The mower will spin for awhile and turn off and show the error code.
What should we do?