Update for you guys..
The z height was incorrect, but I'm not sure what changed. Whenever we set up the robot the pick position was very good and repeatable across the whole table. This was with the height set to 27.5mm. Over time the pick position got worse and worse, I messed with the vision and lighting attempting to improve, and it seemed to help some. Measured the current z height at 45mm. Retaught the reference position in the vision program, program took off.
What could cause this? We have experienced multiple crashes directly in the z axis, which resulted in OVC Alarms and Pulse Mismatch Errors. Could this cause the world frame to move in the -z direction?
I appreciate all the help from you guys!!