A sever generally doesn’t implement any kind of U. You have to do the replication in your pawn or player controller and adapt your UI accordingly on the clients side.

Your Slot refferences dont exist on the Server. Server will never Create any UI. In your Swap Function they will always be null. Think of your UI as read only. Here a nice refference that can explain it better than I can =) UE4_Network_Compendium_by_Cedric_eXi_Neukirchen.pdf 1622.40 KB …