Qusai, I've had the same problem twice (with customers) and found each time that it was indeed a Client-Set or a Destination-Set that has been deleted. Mind that it doesn't has to be deleted the day you restarted the server or just the services. In my case the deletions probably have been made days or weeks earlier, but the services never has been restarted since. So then you come along and does restart them and wonder what the hell you did wrong ! I just found that you should read the !! DATA !! of the registry key looking like :...\FPC\Arrays\{GUID}\ArrayPolicy\Proxy-Access-Rules\{GUID2}\DestSetUsed (or ClientSetUsed according to your problem)\msFPCRefInfo In the data from at least one key you probably will find the GUID which is mentioned in the eventID error. (BTW : each {GUID2} represents an access policy rule. Once you've found the troublemaker (or more than one) you change him in the registry or in the ISA management. I hope this does it for you like it did for me. Good luck, Carlo.