Error interrupt funcition with MPLAB X v5.30 XC8
In XC8, you need to define interrupts this way (the myISR can be changed to whatever you want):

void __interrupt() myISR(void)
{
    //Do something
}


Provided you are compiling against C99. The old void interrupt myISR(void) syntax is from XC8 2.00 or lower. They changed the way interrupts are defined after that. If you are not compiling against C99, you can also try void interrupt() myISR(void) { ... }.