503 error exception

[mystasly48]

I think I clicked Send button but the tweet has not been sent so I clicked again then the exception was thrown.
I continued the exception and I clicked again, the tweet was sent successfully.

See the end of this message for details on invoking 
just-in-time (JIT) debugging instead of this dialog box.

************** Exception Text **************
CoreTweet.TwitterException ---> System.Net.WebException: The remote server returned an error: (503) Server Unavailable.
   at System.Net.HttpWebRequest.GetResponse()
   at CoreTweet.Request.HttpPost(Uri url, String contentType, Byte[] content, String authorizationHeader, ConnectionOptions options)
   at CoreTweet.Request.HttpPost(Uri url, IEnumerable`1 prm, String authorizationHeader, ConnectionOptions options)
   at CoreTweet.Core.TokensBase.SendRequestImpl(MethodType type, String url, IEnumerable`1 parameters, ConnectionOptions options)
   --- End of inner exception stack trace ---
   at CoreTweet.Core.TokensBase.SendRequestImpl(MethodType type, String url, IEnumerable`1 parameters, ConnectionOptions options)
   at CoreTweet.Core.TokensBase.AccessApiImpl[T](MethodType type, String url, IEnumerable`1 parameters, String jsonPath)
   at CoreTweet.Rest.Statuses.Update(String status, Nullable`1 in_reply_to_status_id, Nullable`1 possibly_sensitive, Nullable`1 lat, Nullable`1 long, String place_id, Nullable`1 display_coordinates, Nullable`1 trim_user, IEnumerable`1 media_ids, String attachment_url, Nullable`1 auto_populate_reply_metadata, IEnumerable`1 exclude_reply_user_ids, Nullable`1 include_ext_alt_text, Nullable`1 tweet_mode, Nullable`1 enable_dm_commands, Nullable`1 fail_dm_commands)
   at Mystter_SendTweet.Form1.SendTweet(String msg)
   at Mystter_SendTweet.Form1.sendBtn_Click(Object sender, EventArgs e)
   at System.Windows.Forms.Control.OnClick(EventArgs e)
   at System.Windows.Forms.Button.OnClick(EventArgs e)
   at System.Windows.Forms.Button.PerformClick()
   at Mystter_SendTweet.Form1.textBox1_KeyDown(Object sender, KeyEventArgs e)
   at System.Windows.Forms.Control.OnKeyDown(KeyEventArgs e)
   at System.Windows.Forms.Control.ProcessKeyEventArgs(Message& m)
   at System.Windows.Forms.Control.ProcessKeyMessage(Message& m)
   at System.Windows.Forms.Control.WmKeyChar(Message& m)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.TextBoxBase.WndProc(Message& m)
   at System.Windows.Forms.TextBox.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)


************** Loaded Assemblies **************
mscorlib
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.4200.0 built by: NET48REL1LAST_C
    CodeBase: file:///C:/Windows/Microsoft.NET/Framework/v4.0.30319/mscorlib.dll
----------------------------------------
Mystter
    Assembly Version: 1.4.2.0
    Win32 Version: 1.4.2
    CodeBase: file:///C:/Program%20Files%20(x86)/Mystter/Mystter.exe
----------------------------------------
System.Windows.Forms
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.4200.0 built by: NET48REL1LAST_C
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Windows.Forms/v4.0_4.0.0.0__b77a5c561934e089/System.Windows.Forms.dll
----------------------------------------
System
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.4200.0 built by: NET48REL1LAST_C
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System/v4.0_4.0.0.0__b77a5c561934e089/System.dll
----------------------------------------
System.Drawing
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.3752.0 built by: NET48REL1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Drawing/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll
----------------------------------------
System.Configuration
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.4190.0 built by: NET48REL1LAST_B
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Configuration/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Configuration.dll
----------------------------------------
System.Core
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.4200.0 built by: NET48REL1LAST_C
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Core/v4.0_4.0.0.0__b77a5c561934e089/System.Core.dll
----------------------------------------
System.Xml
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.3752.0 built by: NET48REL1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Xml/v4.0_4.0.0.0__b77a5c561934e089/System.Xml.dll
----------------------------------------
ImageListView
    Assembly Version: 13.8.2.0
    Win32 Version: 13.8.2.0
    CodeBase: file:///C:/Program%20Files%20(x86)/Mystter/ImageListView.DLL
----------------------------------------
Mystter.resources
    Assembly Version: 1.4.2.0
    Win32 Version: 1.4.2
    CodeBase: file:///C:/Program%20Files%20(x86)/Mystter/Languages/ja/Mystter.resources.DLL
----------------------------------------
Microsoft.GeneratedCode
    Assembly Version: 1.0.0.0
    Win32 Version: 4.8.3752.0 built by: NET48REL1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Xml/v4.0_4.0.0.0__b77a5c561934e089/System.Xml.dll
----------------------------------------
CoreTweet
    Assembly Version: 1.0.0.483
    Win32 Version: 1.0.0.483
    CodeBase: file:///C:/Program%20Files%20(x86)/Mystter/CoreTweet.DLL
----------------------------------------
Newtonsoft.Json
    Assembly Version: 12.0.0.0
    Win32 Version: 12.0.3.23909
    CodeBase: file:///C:/Program%20Files%20(x86)/Mystter/Newtonsoft.Json.DLL
----------------------------------------
System.Numerics
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.3752.0 built by: NET48REL1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Numerics/v4.0_4.0.0.0__b77a5c561934e089/System.Numerics.dll
----------------------------------------
System.Runtime.Serialization
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.4200.0 built by: NET48REL1LAST_C
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Runtime.Serialization/v4.0_4.0.0.0__b77a5c561934e089/System.Runtime.Serialization.dll
----------------------------------------
System.Data
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.4200.0 built by: NET48REL1LAST_C
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_32/System.Data/v4.0_4.0.0.0__b77a5c561934e089/System.Data.dll
----------------------------------------

************** JIT Debugging **************
To enable just-in-time (JIT) debugging, the .config file for this
application or computer (machine.config) must have the
jitDebugging value set in the system.windows.forms section.
The application must also be compiled with debugging
enabled.

For example:

<configuration>
    <system.windows.forms jitDebugging="true" />
</configuration>

When JIT debugging is enabled, any unhandled exception
will be sent to the JIT debugger registered on the computer
rather than be handled by this dialog box.