"ERR Wait For User" - Print Fail and Strange Errors
The hardware is a MK3S and MMU2S combination running the latest firmware. The print is a rather large (27 hour) print that failed after many hours at Z=8.3. I assumed it was an issue with the MMU2S - which is generally unreliable and causes most print issues - however I disabled the MMU2S in settings on the second try and the print fails exactly at the same layer. I inspected the Gcode - not that I'm an expert - and I cannot find anything that seems out of the ordinary around that layer. I don't recognize the display messages so I'm at a total loss if I have a hardware, firmware or slicer problem.
This was sliced with PrusaSlicer 2.7.1 for i3 MK3S+ MMU2S Single using Prusament PETG.
After many hours at Z=8.3 I heard beeping and received "ERR - Wait for User":
There was no option to navigate anywhere on the menu, so pressing the control knob miraculously started the print again after reloading the filament:
Does anybody know what those codes are? (F4 looks like the filament selection, 250 looks like the bed temp).
It seemed to start again, and it was very late so I went to bed. Later that morning it eventually failed at around Z=35.54:
It wasn't until a couple of days later I realized that although it had continued to Z=35.54, it had not printed anything. The filament that came out at 8.3 was the last.
Thinking it was yet another issue with the MMU I decided to disable the MMU in the printer and start over again. Since it is sliced for a single filament I did not re-slice it.
With the MMU disabled in the settings the print started again and printed perfectly fine until - drum roll please - hitting Z=8.3, the exact layer of the first error. However this time it was unrecoverable; pressing the control knob did nothing. I hit the reset and have a duplicate of the first failed print.
I should note that there is an infill density layer change at Z=9.2 which obviously wasn't reached either time.
At this point I'm not sure where to go with this print; I don't know if this is a firmware bug related to the 3S+, or 3S+ combined with (a disabled) MMU2S, or a slicer issue or all three. Any thoughts and comments are appreciated.
Separately, I'm really not sure where to go with this MK3S+MMU combination since with the MMU attached my experience over many years is it is extremely unreliably. I have several Prusas starting years back with a MK2 and also a Mini and this one which started out as a MK3 and upgraded to an S then upgraded to an MMU2S so I have the experience to speak to Prusa reliability. I'd hate to walk away from Prusa but I am seriously evaluating the Bambu X1C with the AMS material changer as this seems a very reliable solution.