The 4 wire connector on top is for the laser. The one on the side is for the auxiliary positioning cross and focus switch. Leave that one connected.
I have not encountered those errors.
There are four connectors plus air tube that connect in that area. The Z motor connector and the upper z limit switch connector plug in under the Z motor trim/cover. The laser power and signal connector plugs into the top of the laser module. So does the air. The focus switch connector plugs into the “wart” on the side of the laser module.