For come reason scene object spawning works perfectly in the editor, in build <-(lo)-> editor, build <-(lo)-> build connections but not across the web (editor<->editor always seems to fail). I'm getting the following errors: Found no behaviour for incoming [ClientRpc:InvokeRpcRpcAddFeedEvent] on Spawner (1) (UnityEngine.GameObject), the server and client should have the same NetworkBehaviour instances [netId=6]. UnityEngine.Networking.NetworkIdentity:UNetStaticUpdate() Found no behaviour for incoming [ClientRpc:InvokeRpcRpcTransmitStateOnConnect] on Spawner (UnityEngine.GameObject), the server and client should have the same NetworkBehaviour instances [netId=5]. UnityEngine.Networking.NetworkIdentity:UNetStaticUpdate() This occurs when my friend connects his build to my editor or build across the web. This is random, occurs almost 99% of the time (but sometimes doesn't). This also only occurs across the web. Scene are IDENTICAL. 100% Sure. The scene is pretty simple: It is just a setup prefab with all UI and controllers. The DEBUG inside it is the NWManager with the HUD component. The NW manager is the same I use across the project. Same settings but without online/offline scenes: Its code just adds events to relevant things. Doesn't change normal behaviour. The gamemode code spawns prefrabs periodically. They are spawned on the server and they have SyncTransform. The only possible problem I noticed is that when this error occurs it points to netId=x. When setting the inspector to debug and inspecting NetworkIdentity components across the scene, in some of them the object scene ID differs from the same object on my friends PC.