As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RECEIVED AVNX MAU 2B FAIL MESSAGE IN CRUISE FLIGHT. FOLLOWED QRH. CREW DECLARED EMERGENCY, LANDING WAS UNEVENTFUL. MAINTENANCE ACCOMPLISHED FIM TASK 31-42-00-810-811 AND PERFORMED NIC 4 AND AIOP RESET. OPS CHECK GOOD. MAINTENANCE LATER REPLACED NIC 4 IN MAU 2 PER EMB 170 MM 31-41-04.