MadHatter

@Enigma_M4 Thanks for this response! I wanted to say that this solution, in regards to the my error message, was hard to find. I am going to print this nice tool.

This error I found was difficult to get good guidance about. KB about this error had me calibrating the lift switch, looking for a bad connection on the pcb behind the print cores, and the printer itself said, vaguely, check your bed and print cores. Other posts about this error suggested the most obvious things like "is there chunks of material on you build plate". I did not find any of this to be helpful. I called Ultimaker support and the agent suggested that I re-calibrate the axes alignment. I was going to do this but had not printed guides to test the squareness of the rods. I slept on this and realized this had nothing to do with the probe sensor in question as the probe is testing z axes movement. I continued to look for other posts about the nozzle probe and how it works and this led me to this vid about "Ultimaker 3 Error: Difference between detected height of both PrintCores exceeds realistic values". This seemed to make some sense to me that over time the adjustment of the build plate could end with running out of z axes headroom so the print core probe bottoms out. This worked for me, and I have had the error before and it just went away before by me taking everything apart and putting it back together. I suggest trying this step if you have this error because it is an easy to do.