Default config for a 18f26k22 (needs .dat file added) has MCLRE enabled.  This is because MCLR=INTMCLR or MCLR=EXTMCLR, instead of OFF or ON.

Also good idea to default config for PBADEN=OFF or else PORTB(5:0) pins are configured as analog input.

Just a warning to others, OSCCON  has to be set manually if INTOSC is other than 16Mhz clock.  Lots to look after with PLLEN in OSCTUNE, and in config, the PRICLKEN and PLLCFG bits.

The DEBUG config bits look to be back in latest MPLAB/MPASM 18fxxk22 device .INC files!!!  Yeah.

KENT