- Remove the Multicast, you don’t need it. Do the attaching of cable in the Server side. As long as the cable and the object it is attaching to is replicated it will be replicated to clients.
- You are attaching on the client side on the replicated variable Cube. The problem is, the Cube is probably not been replicated yet until the next few frames. There are 2 ways to fix this:
a. Use RepNotify and attach the cable inside the RepNotify event. This way you can be sure that the Cube is replicated on the client. But do this on Server call so the Server knows it.
b. OR pass the Cube as a parameter for a Server call. But then you have to move your AttachCableToEnd node inside your SpawnACube node so you can pass the object right after creating it. Then you don’t have to wait for the next replication frame to happen.
So in summary, you have 2 problems to deal with: 1) The cube isn’t replicated yet on the client and 2) You are (re-)attaching the cable on the client side so the Server won’t know it.