Tom,
I'm getting an oddball at the moment. Whenever I try and take a heavy cut I am getting the above. The max following error is set high on all axis and is not being exceeded. Initially I thought it was either vibration or dodgy usb. I've moved control box off machine to eliminate any vibration issues and changed usb cables. If it was limit switches or estop I would expect a different error. Any suggestions on which avenue you would suggest to explore 1st for troubleshooting.
Thanks in advance
Richard