We have this problem as well. All 3650 stacks (2-4) and individual devices. Upgraded from 16.09.3a to 16.12.3a. Refer to
CSCvn98703 , CSCvv34465, CSCuq32728 . We experienced a few 7961 randomly unregister many hours after upgrade. The log POLICER_HW_ERROR error was triggered on the interfaces of the phones. Tac suggested possibly cdp/lldp issue, to which no provided fix or workaround would resolve, but a reload did. We upgraded the affected stack up to 16.12.4. The POLICER_HW_ERROR log message was still noticed on different interfaces that went up/down, these interfaces had no phones attached. 12 hours after upgrade to 16.12.4 one of the original phones unregistered, no errors in logs. In researching the logs further back to boot, we believe this was a separate issue and related to ip dhcp address conflict. After dhcp conflict was cleared device registered successfully. Also to add, this switch did have a smaller ip scope for voice, which was increased in the event this could occur again after a power cycle/failure or future upgrade.
