However, I found that the "ascending" problem stated in Brent's first post can still happen (for me at least). There is a bug in the firmware that seems to be triggered by the probe endstop state during homing. The probe MUST be raised before homing again, otherwise the switch state invokes the climbing error. If you've been having issues with G29 failures, then rehoming, it's likely that you stop resetting the probe - this will make matters worse.
I can replicate this - G29 works perfectly as long as I raise the probe before homing. Homing with it down, G29 goes wrong.
Checklist
- Ensure z probe is raised
Home the spider
Drop the probe
Run G29