As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING EMERGENCY LIGHT TEST EXTERIOR LOAD AFT L MESSAGE WAS DISPLAYED. THE FAILURE MESSAGES INCLUDED COMM EMERGENCY R, EMERGENCY L, COMM AFT L, EXT LOADS AFT L. MOVED THE 2L SLIDE TO 2R TO ISOLATE THE PROBLEM. THEN REPLACED THE 2R SLIDE TO FIX THE PROBLEM AND ELIMINATE THE ERROR MESSAGES.