Wanting to know how to do stuff like items.

[ghost]

In my own game that i'm working on, there are items like keys. I want the server and clients sync the key object so when it is destroyed on any client or on the server, it would tell all clients and server to destroy it. I have already tried a variable but it ends up making it where the 1 client would destroy the key but on the server and other clients it wouldn't destroy. Unless i destroy the key with the server, then the key gets destroyed on the clients. I'm using a system to spawn the key when the game realizes that it is the server. This might have to do with the server being able to destroy it and it works but it doesn't when the clients destroy it. The server syncs the key's position. I have tried to do mp_unsync() but all i get is "Data structure with index does not exist." error.

[The-any-Key]

Please check the tutorials.
I think you try change a remote object. That is not possible. You need to send a RPC message to the owner of a synced object and make it destroy it.