Android Question KeyValueStore2 error, null pointer exception

Sub Service_Create
    Private rp As RuntimePermissions
    Main.PUB_InstDir= rp.GetSafeDirDefaultExternal("")
End Sub

Sub Service_Start (StartingIntent As Intent)
    Service.StopAutomaticForeground 'Starter service can start in the foreground state in some edge cases.
    Try
        If File.Exists(Main.PUB_InstDir,"kvs.dat") =  False Then
            Main.kvs.Initialize(Main.PUB_InstDir,"kvs.dat")
            Main.kvs.PutEncrypted("RecNo",0,Main.PASSWORD)
        End If
    Catch
        ExitApplication
    End Try
End Sub

Sub Process_Globals
    Public Const PASSWORD As String = "1234567"
    Public PUB_InstDir As String
    Public kvs As KeyValueStore
End Sub

Sub btn_Clicked
    kvs.PutEncrypted("RecNo",1,PASSWORD)
    Log(1)
End Sub