G-Code Error?

I received this error (Circular Move on Line 21 would exceed joint 8's negative limit) again today on a different machine right after upgrading to 2.7 from 2.6. There isn't a joint 8 (W-axis) command anywhere in this file. Went back to 2.6 and the same file runs fine.

Attached is the file.


This smells a lot like a bug to me.

Here is one of the configs that are messing up for me. Running the above file in the 9axis sim in 2.7 seems to run ok, but not in the attached config. I don't understand what is wrong.

Ran the config as a simulation in a virtual machine, opened up the limits on W to +-1000 inches and ran the file again, and this is what happened. at lines 18-20.

What do your custom M111, M112, M113, M123, and M125 do?

The M111/M112 are on/off vacuum clamping, and M113,M115,M123,M125 activate/deactivate control of the spindles on the W and Z heads. ( I commented them out on my simulation runs. For example if I were running a file using the Z spindle, M113 would allow M3 and M5 to turn that spindle on and off. M123 would connect the spindle on the W head to M3/M5. M115/M125 dis-connect the Z/W spindles from the M3/M5. If I were running a file with the W spindle only, I would issue M115 and M123 (then M3/M5 would control only the W spindle), running both spindles would use M113 and M123 (then M3/M5 would control both spindles). I don't think they are contributing to the problem.

I agree the custom M-codes are not related to this bug. I can reproduce the problem here without them. I'm looking into it more.