"PhotonView with ID 1001 has no method "ChatMessage" that takes 2 argument(s): String, Object[]" ... But it has....

I have got a chat script and it works, but now I wanted to add the player name. The error says that there is no RPC-Function that takes two arguments, but there is:

 [RPC]
     void ChatMessage(string playerName, string msg){
     
         messages.Add (playerName + ": " + msg);
 
     }

And that's how I call the function:

 PhotonView photonView = PhotonView.Get(this);
                 photonView.RPC("ChatMessage", PhotonTargets.All, PhotonNetwork.playerName, new object[]{currentMessage});

Can you help me?