As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GROUND CREW REPORTS MCD DIFFICULT TO OPEN UNKNOWN SUBSTANCE ON DOOR SEAL. REMOVED FROM SERVICE. C/W OPERATIONAL TEST OF MAIN CABIN DOOR. OPS CKS GOOD. COULD NOT DUPLICATE. OK FOR CONTINUED SERVICE IAW AMM TASK 52-11-00-710-802. NO PARTS REPLACED.