BIG-IP Sync-Failover - Sync Failed

if u didnt alterd the HA configs (unicast/multicast) or wired,then you should try to reset the device trust and make it again, try to sync it if it ask for One or more devices has a more recent configuration than the selected device. To overwrite the more recent configuration, you must use the Overwrite Configuration option then click on check box "Overwrite Configuration"

you should be good

Thanks jai