Rigid Tapping with a speed controlled spindle

That could be the issue, to eliminate the G code just run your code in a sim with a simulated spindle.

JT

tnl.lambert wrote:

I'll provide a theory of mine - I use a custom orient code that uses a separate PID loop. It is connected to motion.spindle-index-enable, so the PID loops change over when M19 is called. Will that be an issue?

No, the G-code interpreter has no idea about what is going on in HAL.

The error is actually line N85, which is a G33.1 (since G33.1 is a sticky motion mode, just like G0 G1 G2 G3) without a K word. So is line N90, if you'd get that far.

On line N85 you need to add a G0 or G1, depending on what you wanted this line to do. I'm guessing you intended it to be a G0.