As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF, LANDING GEAR HANDLE WOULD NOT RAISE DURING GEAR RETRACTION AND AIRCRAFT FAILED TO SHIFT FROM GROUND MODE TO FLIGHT MODE. FLIGHT RETURNED TO MSP AND LANDED WITHOUT INCIDENT. MAINTENANCE FOUND NOSE LANDING GEAR STRUT LOW ON FLUID. RESERVICED STRUT TO PROPER LEVELS AND OPERATIONAL CHECK NORMAL ON GEAR SWING.