Disadvantages of Client/Server Architecture?

Cost:
           A dedicated server is required which may expensive because server hard wares,Server operating system and its license are very expensive things because of its features.

Complexity:
         For server management server engineer is required with desired skills,without server knowledge which may risk to work with this network.

Server Failure:
         The entire network resources are belongs to server.some time unluckily server failure cause the entire network down.Some time  there is chance for data loss in server. because of sudden failure.

Server Overload:
        All the functions in the configured by server.So the entire network ,load will come to server.Because some over load server may lag