synchronize Game Timer in Photon

I am making a room timer for photon, the timer working fine for the master but shows null reference for client.
the second else statement in start function shows null reference on client

bool startTimer = false;
double timerIncrementValue;
double startTime;
[SerializeField] double timer = 20;
ExitGames.Client.Photon.Hashtable CustomeValue;

void Start()
    {
        if (PhotonNetwork.player.IsMasterClient)
        {
            CustomeValue = new ExitGames.Client.Photon.Hashtable();
            startTime = PhotonNetwork.Time;
            startTimer = true;
            CustomeValue.Add("StartTime", startTime);
            PhotonNetwork.CurrentRoom.SetCustomProperties(CustomeValue);
        }
        else
        {
            startTime = double.Parse(PhotonNetwork.CurrentRoom.CustomProperties["StartTime"].ToString());
            startTimer = true;
        }
    }

void Update()
    {

        if (!startTimer) return;

        timerIncrementValue = PhotonNetwork.Time - startTime;

        if (timerIncrementValue >= timer)
        {
           //Timer Completed
           //
        }
    }

Hey, just do you know, these are the Unity Matchmaker forums. You’ll likely get better answers over at the Photon Forums.

they are dead now