Instant Interrupts and a 18F8680

I am trying to use the RX1_INT in DT's Instant Interrupts with this chip and I get an error (actually 3 of them):
NODE1.ASM (785) : Symbol not previously defined (RC1IF)
" " (1365) "
" " (1390) "

I have used these great tools before without ever looking under the 'hood'.
Any guidance would be helpful.
Regards.