I am using FAPTIII version 8.10. When I try to "Store to PMC" on the next screen the "I/O by "I/O" key" is greyed out and cannot be selected. I have used this software for years on Powermate, 16M and other controls. I have always used the I/O by I/O key method. Just trying to Load to PMC the same radio button is greyed out. Any idea how to activate the I/O by key button?