As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING PREFLIGHT FOUND MAIN CABIN DOOR VERY HARD TO OPEN WHEN STARTED UP APU GOT CABIN DOOR OPEN CAS RAN QRH WAS UNABLE TO CLEAR .REPEAT WRITE UP CORRECTIVE ACTION: REPLACED THE CABIN DOOR THRESHOLD HARNESS. PERFORMED CABIN DOOR RESET PROCEDURE. IAW CE-680A AMM 52-10-00. OPS CHECK GOOD.