As you already know Microsoft releases a Cumulative update every month. This update not only includes application fixes but also new client and server components. Recently I ran into a problem after copying the dll’s of the RTC and Service manually. When I restarted the service and try to connect I got stuck.
Instead of opening the client, I got the not very much saying error “The server ‘DynamicsNAV80’ was unable to process the request. The application will close”.
So, my reflex was to go to the server and check the Event Log.
There I found an even more none saying error “An item with the same key has already been added”.