Code crashing

The code has gone bad.  It is in debug mode and jumping around everywhere

Error = "the process or thread has changed since last step"

Here is the code... I just create the file "start.csv" to initialize the shell command.  This is very unstable for some reason.  When I run line by line in debug mode it starts jumping around irrationally.  It gives me versions of the above error.

Option Strict On
Option Explicit On
Imports System.IO


Module Module1

    Public WithEvents Tmr As New Timers.Timer

    Sub Main()
        Console.WriteLine("Worker is Inactive...")
        'WORKER RUN
        Tmr.Interval = 4000 'Interval where Tmr_Tick is kicked off
        Tmr.Enabled = True
        Tmr.Start()
        Console.ReadLine() 'this prevents the console from closing

    End Sub

    Sub Tmr_Tick() Handles Tmr.Elapsed
        Dim Filepath_Executable As String
        Filepath_Executable = "C:\Users\Administrator\Desktop\Machine\Jobs\CurrentJob\Slave1"
        If File.Exists(Filepath_Executable + "\" + "Start.csv") Then 'Status_File
            Shell(Filepath_Executable + "\" + "program.exe")
            Console.Clear()
            Console.WriteLine("Worker Started Application...")
            ' If File.Exists(Filepath_Executable + "\" + "Start.csv") Then File.Delete(Filepath_Executable + "\" + "Start.csv")
            'Dim ioFile As New StreamWriter(Filepath_Executable & "running.csv")
            'ioFile.Close()
        End If
    End Sub

End Module