GRBL - Unsupported or invalid g-code command found in block

[craignicholls (craig)]

Hi there, I am unsure which is line 2 in the below output, and why this is failing… (is this G91?) any help truly apprecaited as to what might be causing it to fail.

ok
Starting stream
Layer C00
error:20
Unsupported or invalid g-code command found in block.
On or near line 2:
Job halted
Stream completed in 0:00

; LightBurn 1.4.04
; GRBL device profile, current position
; Bounds: X-1.67 Y0.06 to X164.37 Y119.16
G00 G17 G40 G21 G54
G91
M4
; Scan @ 4000 mm/min, 30% power
M8
G0 X6.535Y23.507
M3
; Layer C00
G1 X1.667F4000S0
G1 X0.894S300
G1 X1.666S0
G1 X0.161Y0.1S0
G1 X-1.666S0
G1 X-1.206S300
G1 X-1.666S0

[Dskall (D Kallenberger)]

Your problem is probably with M4
Another M4 error with DLC32 V2.1.003 - LightBurn Hardware Compatibility / GRBL - LightBurn Software Forum

[craignicholls (craig)]

Thanks @Dskall it was indeed a firmware issue…

Interestingly for any others trying, I was unable to update the firmware or even connect via the USB/Comport with the TFT and motors etc…attached to the MKS DLC32 v2.1… so, took it back to the bare board and managed to flash the board to the working version from the linked post.

All working correctly, and now with full USB and WIFI connections, happy Lightburn user.

Apprecaite the help in gaining a resolution.!

[Dskall (D Kallenberger)]

Apparently, the screen takes up the usb port or somehow interferes with it.