There are a few reasons for that. The most common is the client and the server are out of sync. That usually happens whgen the game is started with rohanclient.exe rather than through the launcher - which happens to synchronize the data at both ends. Other reasons surround your client machine. You need directx 9.0c and up to date video drivers.
Hello i used launcher to start game and asked 3 other people if they could see the weapon. Only thing that they were able to see was my frost aura.