I was having the same problem yesterday.
Biggest mistake was UCCNC version. I was 1.2037.
Upgraded to 041, and got my copy of default profile working. Works like a charm.
My 2017 profile doesn't. I'm sure I bungled it up trying to get it to work last night.
However, a fresh install of 2017, and then a profile copied from the working profile still will not start the spindle. I'm done for the day, but watching with interest....