As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB AT 18000 FEET, NR 1 ENGINE OIL FILTER CLOGGED LIGHT CAME ON. AS PER QRH, NR 1 ENGINE WAS SHUT DOWN. AIRCRAFT RETURNED TO STATION WITH NO FURTHER PROBLEM. THE OIL FILTER WAS REPLACED. NO SIGNIFICANT CONTAMINATION WAS NOTICED. THE OIL SYSTEM WAS DRAINED AND SERVICED AS PER MM. THE OIL DIFFERENTIAL PRESSURE SWITCH WAS REPLACED. A TEST FLIGHT WAS PERFORMED AND THE ENGINE OIL INDICATION SYSTEM WAS NORMAL. AIRCRAFT WAS RETURN TO SERVICE.