Причиной ошибки могла послужить установка какого-то обновления в IE или другое событие приведшее к изменению настроек браузера.

Закрыто.

************** Exception Text **************
System.Net.WebException: The underlying connection was closed: An unexpected error occurred on a receive. ---> System.IO.IOException: Unable to read data from the transport connection: Удаленный хост принудительно разорвал существующее подключение. ---> System.Net.Sockets.SocketException: Удаленный хост принудительно разорвал существующее подключение
   at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags)
   at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
   --- End of inner exception stack trace ---
   at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
   at System.Net.PooledStream.Read(Byte[] buffer, Int32 offset, Int32 size)
   at System.Net.Connection.SyncRead(HttpWebRequest request, Boolean userRetrievedStream, Boolean probeRead)
   --- End of inner exception stack trace ---
   at System.Net.HttpWebRequest.GetResponse()
   at COMBOTS.Main.GetCurrentVersionFromServer()
   at COMBOTS.Main.pu9u2qteo(Object , EventArgs )
   at System.Windows.Forms.Form.OnLoad(EventArgs e)
   at System.Windows.Forms.Form.OnCreateControl()
   at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
   at System.Windows.Forms.Control.CreateControl()
   at System.Windows.Forms.Control.WmShowWindow(Message& m)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
   at System.Windows.Forms.ContainerControl.WndProc(Message& m)
   at System.Windows.Forms.Form.WmShowWindow(Message& m)
   at System.Windows.Forms.Form.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: 2.0.0.0
    Win32 Version: 2.0.50727.3603 (GDR.050727-3600)
    CodeBase: file:///C:/WINDOWS/Microsoft.NET/Framework/v2.0.50727/mscorlib.dll
----------------------------------------
MC
    Assembly Version: 3.0.0.0
    Win32 Version: 2.0.50727.3603 (GDR.050727-3600)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_32/mscorlib/2.0.0.0__b77a5c561934e089/mscorlib.dll
----------------------------------------
System.Windows.Forms
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.3053 (netfxsp.050727-3000)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Windows.Forms/2.0.0.0__b77a5c561934e089/System.Windows.Forms.dll
----------------------------------------
System
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.3053 (netfxsp.050727-3000)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System/2.0.0.0__b77a5c561934e089/System.dll
----------------------------------------
System.Drawing
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.3053 (netfxsp.050727-3000)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Drawing/2.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll
----------------------------------------
??????????????????
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.3603 (GDR.050727-3600)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_32/mscorlib/2.0.0.0__b77a5c561934e089/mscorlib.dll
----------------------------------------
License
    Assembly Version: 1.0.0.0
    Win32 Version: 2.0.50727.3603 (GDR.050727-3600)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_32/mscorlib/2.0.0.0__b77a5c561934e089/mscorlib.dll
----------------------------------------
System.Management
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.3053 (netfxsp.050727-3000)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Management/2.0.0.0__b03f5f7f11d50a3a/System.Management.dll
----------------------------------------
Combots
    Assembly Version: 8.5.0.0
    Win32 Version: 2.0.50727.3603 (GDR.050727-3600)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_32/mscorlib/2.0.0.0__b77a5c561934e089/mscorlib.dll
----------------------------------------
Interop.SHDocVw
    Assembly Version: 1.1.0.0
    Win32 Version: 1.1.0.0
    CodeBase: file:///C:/Program%20Files/Combots/Interop.SHDocVw.DLL
----------------------------------------
System.Configuration
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.3053 (netfxsp.050727-3000)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Configuration/2.0.0.0__b03f5f7f11d50a3a/System.Configuration.dll
----------------------------------------
System.Xml
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.3082 (QFE.050727-3000)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Xml/2.0.0.0__b77a5c561934e089/System.Xml.dll
----------------------------------------
Microsoft.JScript
    Assembly Version: 8.0.0.0
    Win32 Version: 8.0.50727.3053
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Microsoft.JScript/8.0.0.0__b03f5f7f11d50a3a/Microsoft.JScript.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.                                                                                                                                                         

Что делать незнаю(