As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR DIVERSION TO EWR WAS IAD - AMSL2 DOOR NOT ARMED PRIOR TO T/O OUT OF IAD TO AMS.F/A UNABLE TO ARM IN FLT.THE TOMC CONTROLLER AND SENIOR MANAGER CONCUR THAT THE AIRCRAFT CAN BE RELEASED BACK TO SERVICE AFTER EXPERIENCING A DIVERSION O R AIR TURN BACK DUE TO A MECHANICAL REASON LOCKED BY SYSTEM. UNLOCKED FOR SIGN OFF SLIDE AT 2L ARMED AND DISARMED SEVERAL TIMES AND INSPECTED FOR CORRECT INSTALLATION AND OPERATION. NO ISSUED DETECTED. REF AMM 25-66-01.