Re: MCC making errors? / Missing prototypes
Some of the possibilities might be:
Not selecting to use Interrupts for Interrupt On Change for Port A,
Doing changes in MCC configuration, and then forgetting to click Generate before trying to build the program.
Not setting up the Interrupt module.
Bug in MCC is certainly a possibility, MCC do not work by magic, there are scripts that have been prepared by human program developers.
Do you really want the extra overhead of using function call by pointer to the ISR handler for IOC interrupt?
You may put in the code you need at: "// Add custom IOCAF3 code "
and remove the: "IOCAF3_InterruptHandler(); " stuff.