The message usually comes from the switch that is connected to the AP. This message should not affect any traffic accross the AP.
By implementing these steps you will no longer receive this warning on your Access Point.
Step 1 Under Summary Status page ---> Goto Setup tab.
Step 2 Under Event Log ---> Goto Event Handling ---> Goto Network Port Warning and set the option
to Count.
Step 3 Under Event Log ---> Goto Event Handling ---> Goto External Warning and set the option to
Count.
Step 4 Click Apply --> click ok