Hidden filed return null exception when I call a property of another user control (.ascx) from a user control page (.ascx)

Question

I have calling a property from a user control, and it return me an exception - object reference not set to an instance of an object

• Below is part of my code

This is my property Max_Pocket_Value from a user control

Public Property Max_Pocket_Value_() As Integer
        Get
            Dim MAXIMUM_VALUE As Integer
            Try

                Dim MAXIMUM_VALUE1 As String = Me.hf_MaxPocketNumber.Value
                Integer.TryParse(Me.hf_MaxPocketNumber.Value, MAXIMUM_VALUE)
                Dim B As Integer = MAXIMUM_VALUE
                If MAXIMUM_VALUE < 0 Then
                    MAXIMUM_VALUE = -1
                End If
            Catch ex As Exception
                MsgBox("Can't load Web page" & vbCrLf & ex.Message)
            End Try



            Return MAXIMUM_VALUE

        End Get
        Set(max_Pocket_Number As Integer)
            hf_MaxPocketNumber.Value = max_Pocket_Number.ToString()
        End Set
    End Property

I set the property value on Page_Init. dataPiece(0).Max_Pocket_ have value of : 9 during debug session

    Private Sub Page_Init(sender As Object, e As EventArgs) Handles Me.Init

        data_Grabber_()
        Me.Max_Pocket_Value_ = dataPiece(0).Max_Pocket_
    End Sub`

I call the property on current ascx apge in page_load, and I did tried call the propery in page_init.It result me same exception

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
    Dim pocketControl As New GridTableUserControl()
    Dim abc As Integer = pocketControl.Max_Pocket_Value_

End Sub

The exception is catch on line below

Public Property Max_Pocket_Value_() As Integer
    Get
        Dim MAXIMUM_VALUE As Integer
        Try

            Dim MAXIMUM_VALUE1 As String = Me.hf_MaxPocketNumber.Value
   **here -->** Integer.TryParse(Me.hf_MaxPocketNumber.Value, MAXIMUM_VALUE)
            Dim B As Integer = MAXIMUM_VALUE
            If MAXIMUM_VALUE < 0 Then
                MAXIMUM_VALUE = -1
            End If
        Catch ex As Exception
            MsgBox("Can't load Web page" & vbCrLf & ex.Message)
        End Try



        Return MAXIMUM_VALUE

    End Get
    Set(max_Pocket_Number As Integer)
        hf_MaxPocketNumber.Value = max_Pocket_Number.ToString()
    End Set
End Property

Is anyone know what is the issue? Would highly appreciated if I can find some idea here. Thanks!