I dont know the answer, but I can think of some more questions..
what year is this machine?
What model is the machine?
what spindle controller is it?
I do have a simular issue, and you can try this....
My startup MUST be like this for my machine to work.
Go to MDI
If I do not do a spindle start in MDI before anything else, it will fault out on a spindle error of 28 I think it is.
Mine is a 93 VMC15 with a Baldor drive wye/delta