I have recently taken over management of my customers UC540 (2 units at 2 sites, site to site VPN for voice and data), because of the lack of knowledge of their prior support team. Being new to Cisco and their configurations, I have spent the weekend reading and studying the 656 page admin guide. So far so good, until I try to access the multisite manager (configure / telephony / site management). When I try to access that area, the CCA comes back with "there is an error in your multisite configuration", specifically "A matching NAT ACE is missing for existing crypto ACE". One option is to remove existing configuration, which I am hesitant to do (the other option is cancel and manually reconcile the configuration). Although I am fairly confident I can re-configure it, being new to the UC540, I'm not sure. Exhaustive searching has not brought up any help with this particular error, and I don't know exactly what to look for or where to look to manually resolve the configuration. Any help or idea would be greatly appreciated.