[Visual Basic TCP] Length cannot be less than zero. Parameter name: length

Dim serverSocket As New TcpListener(1200)
        Dim clientSocket As TcpClient
        Dim counter As Integer

        serverSocket.Start()
        msg("Chat Server Started.")
        counter = 0

        While (True)
            counter += 1
            clientSocket = serverSocket.AcceptTcpClient()

            Dim bytesFrom(10024) As Byte
            Dim dataFromClient As String
            Dim networkStream As NetworkStream = _
            clientSocket.GetStream()
            networkStream.Read(bytesFrom, 0, CInt(clientSocket.ReceiveBufferSize))
            dataFromClient = System.Text.Encoding.ASCII.GetString(bytesFrom)
            dataFromClient = dataFromClient.IndexOf("$")

            clientsList(dataFromClient) = clientSocket

            broadcast(dataFromClient + " Joined ", dataFromClient, False)

            msg(dataFromClient + " Joined chat room ")
            Dim client As New handleClinet
            client.startClient(clientSocket, dataFromClient, clientsList)
        End While