Recently I encountered an issue when attempting to publish a FAIR to Net-Inspect. I received the error message (repeated twice) "The Primary datum has not yet been defined"
After working with the help desk we were able to conclude that one of the (very many) GD&T characteristics had something wrong with the data collected by OCR or by hand in the feature frame, primary datum box.
To correct the issue I had to revisit each characteristic and examine it very closely to see if I could detect the error. This took quite a bit of time. It would have been much simpler and faster if the original error message included the balloon number of the offending characteristic.