grblHAL Error 45

grblHALErrorPosition is kept

A limit switch is pressed, so only homing is allowed.

Position is kept. An error means the controller refused that one line or command, so nothing moved for it. (Hamrun's reading)

What to do

Home the machine, or jog it off the switch.
If nothing is touching the switch, check its wiring.

What users reported CLAIMED · forum and issue reports, not official

First-run alarm stops on a Genmitsu 4040: the machine wasn't homed, or was parked against a limit switch. Home first, unlock, then check the job. It was the alarm state, not a dead board. r/hobbycnc thread, Jan 2026 (the thread doesn't name the alarm number)

Official grblHAL message: “Only homing is allowed when a limit switch is engaged.” source

Got a different message?

Paste it into the decoder. Hamrun's editor checks your G-code before you run it, so a toolpath that leaves the machine's travel or a missing feed rate is caught before the machine stops.

Official text copied from the grblHAL source on 2026-11-01. Steps and the position answer are Hamrun's reading unless marked “firmware says”. User reports are labelled CLAIMED.