C#

[StructLayout(LayoutKind.Sequential)]
private struct LINEINITIALIZEEXPARAMS
{
    public uint dwTotalSize;
    public uint dwNeededSize;
    public uint dwUsedSize;
    public uint dwOptions;
    public IntPtr handle; // Will be either hEvent OR hCompletionPort
    public uint dwCompletionKey;
}

IntPtr hInstance = System.Diagnostics.Process.GetCurrentProcess().Handle;

/// <summary>
/// No error.
/// </summary>
public const uint LINEERR_NOERROR = 0x00000000;
/// <summary>
/// Invalid application name.
/// </summary>
public const uint LINEERR_INVALAPPNAME = 0x80000015;
/// <summary>
/// The INI file is corrupted.
/// </summary>
public const uint LINEERR_INIFILECORRUPT = 0x8000000E;
/// <summary>
/// Invalid parameter.
/// </summary>
public const uint LINEERR_INVALPARAM = 0x80000032;
/// <summary>
/// Invalid pointer.
/// </summary>
public const uint LINEERR_INVALPOINTER = 0x80000035;
/// <summary>
/// No memory available.
/// </summary>
public const uint LINEERR_NOMEM = 0x80000044;
/// <summary>
/// The operation failed.
/// </summary>
public const uint LINEERR_OPERATIONFAILED = 0x80000048;
/// <summary>
/// The application attempted to initialize TAPI twice.
/// </summary>
public const uint LINEERR_REINIT = 0x80000052;

public bool OpenLine()
{
    UInt32 dwDevNum = 0;//count the devices
    UInt32 dwApiVerSion = TAPI_CURRENT_VERSION;
    LINEINITIALIZEEXPARAMS dtParams = new LINEINITIALIZEEXPARAMS();
    dtParams.dwTotalSize = (UInt32)Marshal.SizeOf(dtParams);
    dtParams.dwOptions = 1;
    IntPtr handles = new IntPtr(0);

    IntPtr hInstance = IntPtr.Zero;//new IntPtr(GetModuleHandle(new IntPtr(0)).ToInt32());
    unsafe
    {
        fixed(IntPtr *hLineApp = &m_hLineApp)
        {
            long lResult = lineInitializeEx(hLineApp, hInstance, new IntPtr(0), new IntPtr(0),
                new IntPtr(&dwDevNum), new IntPtr(&dwApiVerSion), new IntPtr(&dtParams));
            if (lResult == 0)
            {
                return true;
            }
        }
        return false;
    }
}
[StructLayout(LayoutKind.Sequential)]
private struct LINEINITIALIZEEXPARAMS
{
    public uint dwTotalSize;
    public uint dwNeededSize;
    public uint dwUsedSize;
    public uint dwOptions;
    public IntPtr hMultiUse;
    public uint dwCompletionKey;
}
[DllImport("coredll.dll", SetLastError = true)]
unsafe private static extern uint lineInitializeEx(
    IntPtr *lphLineApp,
    IntPtr hInstance,
    IntPtr pfnCallback,//lineCallbackFunc lpfnCallback,
    IntPtr FriendAppName,//StringBuilder lpszFriendlyAppName,
    IntPtr pNumDevs,//out uint lpdwNumDevs,
    IntPtr pAPIVersion,//out uint lpdwAPIVersion,
    IntPtr pLineInitializeExParams);//ref LINEINITIALIZEEXPARAMS lpLineInitializeExParams);

srng.net wrote:

Could you please guide me regarding any possible reason for the same?

srng.net wrote:

My point of view, This can not be becasue of third party tool. Reason : Again we can look into the StackTrace where the exception is raised by System.Windows.forms.dll and third party tool is just passing comand to WM_ExitSizeMove and leaving the handle to windows.