.net application crashes without an error

I wrote an application in VB.Net, and somehow it crashes without a reason, for example I run it, it started successfully then after staying non-active for like 10 or more minutes it crashes, without any exception and Visual Studio tells me that process switched to stop mode and application was closed.

My main code isn't looping except that a timer is always enabled with 100ms period, i don't think this is a problem. The funny thing is that the time when process will crash varies.

I tried my application on two Win10 machines. On one of them it doesn't crash at all, and on the other one sometimes crashes. And I tried on Win7, crashes happen regularly after 20min - Windows says "application is not responding, we are closing the app". So why it doesn't show any exceptions in debug mode of VS17, also i turned on all exceptions in debug menu. first is net runtime log and second is application log:

Имя журнала:   Application
Источник:      .NET Runtime
Дата:          28.04.2018 18:40:02
Код события:   1026
Категория задачи:Отсутствует
Уровень:       Ошибка
Ключевые слова:Классический
Пользователь:  Н/Д
Компьютер:     HV-service-ПК
Описание:
Application: SD CARD Car Master [beta].exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.ObjectDisposedException
Stack:
   at System.Runtime.InteropServices.SafeHandle.DangerousAddRef(Boolean ByRef)
   at System.StubHelpers.StubHelpers.SafeHandleAddRef(System.Runtime.InteropServices.SafeHandle, Boolean ByRef)
   at Microsoft.Win32.UnsafeNativeMethods.GetOverlappedResult(Microsoft.Win32.SafeHandles.SafeFileHandle, System.Threading.NativeOverlapped*, Int32 ByRef, Boolean)
   at System.IO.Ports.SerialStream+EventLoopRunner.WaitForCommEvent()
   at System.Threading.ThreadHelper.ThreadStart_Context(System.Object)
   at System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
   at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
   at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object)
   at System.Threading.ThreadHelper.ThreadStart()

Xml события:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name=".NET Runtime" />
    <EventID Qualifiers="0">1026</EventID>
    <Level>2</Level>
    <Task>0</Task>
    <Keywords>0x80000000000000</Keywords>
    <TimeCreated SystemTime="2018-04-28T07:40:02.000000000Z" />
    <EventRecordID>533</EventRecordID>
    <Channel>Application</Channel>
    <Computer>HV-service-ПК</Computer>
    <Security />
  </System>
  <EventData>
    <Data>Application: SD CARD Car Master [beta].exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.ObjectDisposedException
Stack:
   at System.Runtime.InteropServices.SafeHandle.DangerousAddRef(Boolean ByRef)
   at System.StubHelpers.StubHelpers.SafeHandleAddRef(System.Runtime.InteropServices.SafeHandle, Boolean ByRef)
   at Microsoft.Win32.UnsafeNativeMethods.GetOverlappedResult(Microsoft.Win32.SafeHandles.SafeFileHandle, System.Threading.NativeOverlapped*, Int32 ByRef, Boolean)
   at System.IO.Ports.SerialStream+EventLoopRunner.WaitForCommEvent()
   at System.Threading.ThreadHelper.ThreadStart_Context(System.Object)
   at System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
   at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
   at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object)
   at System.Threading.ThreadHelper.ThreadStart()
</Data>
  </EventData>
</Event>

Имя журнала:   Application
Источник:      Application Error
Дата:          28.04.2018 18:31:18
Код события:   1000
Категория задачи:(100)
Уровень:       Ошибка
Ключевые слова:Классический
Пользователь:  Н/Д
Компьютер:     HV-service-ПК
Описание:
Имя сбойного приложения: SD CARD Car Master [beta].exe, версия: 1.0.0.0, отметка времени: 0x5ae2a828
Имя сбойного модуля: KERNELBASE.dll, версия: 6.1.7601.17514, отметка времени 0x4ce7b8f0
Код исключения: 0xe0434352
Смещение ошибки: 0x0000b760
Идентификатор сбойного процесса: 0xc9c
Время запуска сбойного приложения: 0x01d3dec2dcbdc3d0
Путь сбойного приложения: C:\Users\HV-service\Desktop\SD CARD Car Master [beta].exe
Путь сбойного модуля: C:\Windows\system32\KERNELBASE.dll
Код отчета: 238f20b0-4ab6-11e8-b866-001b3822ff72
Xml события:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name="Application Error" />
    <EventID Qualifiers="0">1000</EventID>
    <Level>2</Level>
    <Task>100</Task>
    <Keywords>0x80000000000000</Keywords>
    <TimeCreated SystemTime="2018-04-28T07:31:18.000000000Z" />
    <EventRecordID>531</EventRecordID>
    <Channel>Application</Channel>
    <Computer>HV-service-ПК</Computer>
    <Security />
  </System>
  <EventData>
    <Data>SD CARD Car Master [beta].exe</Data>
    <Data>1.0.0.0</Data>
    <Data>5ae2a828</Data>
    <Data>KERNELBASE.dll</Data>
    <Data>6.1.7601.17514</Data>
    <Data>4ce7b8f0</Data>
    <Data>e0434352</Data>
    <Data>0000b760</Data>
    <Data>c9c</Data>
    <Data>01d3dec2dcbdc3d0</Data>
    <Data>C:\Users\HV-service\Desktop\SD CARD Car Master [beta].exe</Data>
    <Data>C:\Windows\system32\KERNELBASE.dll</Data>
    <Data>238f20b0-4ab6-11e8-b866-001b3822ff72</Data>
  </EventData>
</Event>

Update: I noticed that the problem in the serial port autoconnect code:

  Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

        Connected = False
   autoconnect()
    End Sub
 Private Sub autoconnect()

        For Each sp As String In My.Computer.Ports.SerialPortNames
            Try
                spObj = New SerialPort(sp, 115200, Parity.None, 8, StopBits.One)
                spObj.ReadTimeout = 5000
                '    spObj.ReceivedBytesThreshold = 6
                spObj.WriteTimeout = 5000
                spObj.Open()

                Dim ListeningWatch As New Stopwatch
                Dim serialMessage As String

                Dim BytesToSend(1) As Byte
                Dim OutBuffer
                BytesToSend(0) = Hex(99)             ' call Dump eeprom (44)
                BytesToSend(1) = 0                   'dummy
                OutBuffer = BytesToSend

                ' Bytes are outputted in the order of their Index Number(Index)!

                spObj.Write(OutBuffer, 0, OutBuffer.length)

                ListeningWatch.Start()
                While ListeningWatch.ElapsedMilliseconds < 5000 And ListeningWatch.IsRunning
                    serialMessage = spObj.ReadExisting()
                    'RichTextBox1.Text = serialMessage
                    If serialMessage.Contains("000001020") And serialMessage.Length = 12 Then
                        ListeningWatch.Stop()

                        Connected = True
                        Timer1.Enabled = False
                        DeviceStatus.Text = "SN: " & serialMessage                       
                        Exit For
                    End If
                End While
            Catch ex As Exception
                spObj.Dispose()
            End Try
        Next
        If Connected = False Then
            DeviceStatus.Text = "SN: Not connected"
        End If
    End Sub