# Error Code 33 Halts work (Stops Play)

**URL:** <https://forum.sienci.com/t/error-code-33-halts-work-stops-play/16897>\
**Category:** UGS\
**Created:** [April 13, 2025, 1:29pm UTC](https://forum.sienci.com/t/error-code-33-halts-work-stops-play/16897 "2025-04-13T13:29:39Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![gwilki](https://forum.sienci.com/user_avatar/forum.sienci.com/gwilki/32/366_2.png) [@gwilki](https://forum.sienci.com/u/gwilki)\
**Post date:** [April 13, 2025, 1:51pm UTC](https://forum.sienci.com/t/error-code-33-halts-work-stops-play/16897/2 "2025-04-13T13:51:37Z")

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@buggalugs Welcome to the group, Eddie.

It’s been years since I’ve used UGS, but here is an explanation of that error code in the gSender documentation

### Error 33

Can pop up as “Motion command target is invalid” and usually comes from issues with G2 or G3 arc/curve movements in the g-code. If the target is invalid you might want to verify the file again in gSender or regenerate it in CAM with the right post processor.

For example, there have been [many](https://forum.sienci.com/t/invalid-g-code-id-33-in-gsender/10904) [reports](https://community.carbide3d.com/t/grbl-error-invalid-gcode-id-33/1204) that if you use the `inch` post processor in Vectric, Carveco, or Fusion 360 then they won’t add enough decimal places to satisfy arc curve calculations – which will cause an Error 33. The best solution is to just use a `mm` post processor to get more accurate movements, or for Carveco use `UGS grbl`.

You may also want to ask on the UGS forum. Good luck. Please post back when you find the solution.

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