Basic Information: Printer Model: Voron Trident 300 MCU / Printerboard: Octopus Pro v1 Host / SBC: RPI 4 klippy.log klippy.zip (919.0 KB) My printer was working fine yesterday, successfully finished a print, but today when trying to print I started to get: b'stepcompress o=0 i=0 c=10 a=0: …

[image] The "dirty" Flag and the Team's Position Knowledge Base Background Klipper’s main-line code is published on GitHub . Upon start, Klipper checks if the locally installed code is the same as the code published in this official repository. If not, the code …

Thanks for taking a look! I haven’t upgraded anything in around a month and I’ve printed tens of hours with the current configuration and software versions. It worked yesterday evening and stopped working today when trying to reprint the same file that worked yesterday. What makes you think it’s …

Hi @Leonti , My guess is it’s HH since I’m not aware of Carto messing with the extruder. One way you could test would be to comment out the [include mmu/...] lines at the top of your printer.cfg and manually load filament to your toolhead and run test a print. If it succeeds, then the issue is lik…

I’ve had VERY mixed results using AI on klipper problems. I normally make it cite sources and half the time they are COMPLETE fabrications. Last time I tried it cited 2 git repos… both came back 404. Use the following at your own risk. I asked AI (Claude) to summarize your shutdown logs. It barfed …

I think it is related to Happy Hare. I was printing those prints with MMU_ENABLE = 0, once I went back to MMU_ENABLE = 1 I haven’t had this problem since (5 prints already). I’m still confused though, since I did a print yesterday with MMU_ENABLE = 0 and it was successful. Same GCODE the next day …

I just want to report I had the exact same issue as Leonti . No updates or changes made, mmu enable=0 was working fine one day. The next day I went to print something the same way and the same problems occurred. After turning the MMU back on and using it works fine. I have not tried going back to m…

Welcome Poisson, It’s always a good idea to post a klippy.log after such a finding. From a klippy.log we may find reasons for that error.

Sure, here it is klippy(12).zip (1.8 MB)

The only thing that I can say for now is that it seems that regardless of specific Klipper version, every time I see a similar error, there is an MMU defined in the config. I guess the only similarity that I can pinpoint is: b'stepcompress o=2 i=0 c=9 a=0: Invalid sequence' ... stepcompress error …

Investigated and I have a suspicion: Under the motion_queuing model that klipper has implemented late last year, I believe each stepper’s step generator has a scan window that looks ahead/behind print_time. When the extruder (don’t forget, HH treats the MMU stepper as an “extruder” that is “attach…

Error in syncemitter 'extruder' step generation

General Discussion

cardoc May 2, 2026, 3:27am 2

A quick look at your logs makes me feel your issue is in the Cartographer and/or Happyhare routines or hardware. Both are known to break on klipper upgrades.

You may want to reach out to them. Let us know if they are no help.

Good luck

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Error in syncemitter 'extruder' step generation

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