Problem with ImageManager in v17.3.0

I have a CIconCheckBox class which is derived from CXTPButton class.  This function for setting ImageManager:

void CIconCheckBox::SetImageManager(CXTPImageManager* pImageManager)

{

    if (pImageManager && m_pMarkupContext)

    {

        m_pMarkupContext->SetImageManager(pImageManager);

        CMDTARGET_ADDREF(pImageManager);

    }

    else

        ASSERT(0);

}

This checkbox is then initialized in a dialog as follow

CMyDialog::OnInitDialog()

{

    BOOL result = CXTPPropertyPage::OnInitDialog();

    // m_imageManager & m_checkbox are members of CMyDialog

    m_imageManager.SetImageList(IDB_IMAGELIST, 16);

    m_checkbox.SubclassDlgItem(IDC_CHECKBOXID, this);

    m_checkbox.SetImageManager(&m_imageManager);

    m_checkbox.SetImage(0);

}

This code works well in v16.2.4 & Visual Studio 2012. However, after being upgraded to v17.3.0 & Visual Studio 2015, exception always occurs in CXTPImageManagerIconHandle::GetBitmap() because of hBitmap=null and m_pRInfo=null.

HBITMAP CXTPImageManagerIconHandle::GetBitmap() const

{

    ASSERT(IsAlpha());

    if (m_hBitmap)

        return m_hBitmap;

    if (m_pRInfo && m_pRInfo->pResource && m_pRInfo->pResource->m_hbmpImage)

        return m_pRInfo->pResource->m_hbmpImage;

    ASSERT(FALSE);

    return NULL;

}

// Call Stack for reference

ToolkitPro1730vc140UD.dll!CXTPImageManagerIconHandle::GetBitmap() Line 1320           C++

ToolkitPro1730vc140UD.dll!CXTPMarkupGdiPlusDeviceContext::IconToGdiplusBitmap(CXTPImageManagerIcon * pIcon) Line 781   C++

ToolkitPro1730vc140UD.dll!CXTPMarkupGdiPlusDeviceContext::DrawImage(CXTPImageManagerIcon * pIcon, CRect rc) Line 799     C++

ToolkitPro1730vc140UD.dll!CXTPMarkupGdiPlusDeviceContext::DrawImage(CXTPMarkupDeviceDependentImage * pImage, CRect rc) Line 872               C++

ToolkitPro1730vc140UD.dll!CXTPMarkupDrawingContext::DrawImage(CXTPMarkupDeviceDependentImage * pImage, CRect rc) Line 845         C++

ToolkitPro1730vc140UD.dll!CXTPMarkupImage::OnRender(CXTPMarkupDrawingContext * pDC) Line 230           C++

ToolkitPro1730vc140UD.dll!CXTPMarkupVisual::Render(CXTPMarkupDrawingContext * drawingContext) Line 878              C++

ToolkitPro1730vc140UD.dll!CXTPMarkupVisual::Render(CXTPMarkupDrawingContext * drawingContext) Line 884              C++

ToolkitPro1730vc140UD.dll!XTPMarkupRenderElement(CXTPMarkupUIElement * pElement, HDC__ * hDC, const tagRECT * lpRect) Line 131  C++

ToolkitPro1730vc140UD.dll!CXTPButtonTheme::DrawButtonText(CDC * pDC, CXTPButton * pButton) Line 418   C++

ToolkitPro1730vc140UD.dll!CXTPButtonTheme::DrawButton(CDC * pDC, CXTPButton * pButton) Line 119          C++

ToolkitPro1730vc140UD.dll!CXTPButton::DoDraw(CDC * pDC) Line 396                C++

ToolkitPro1730vc140UD.dll!CXTPButton::OnDraw(CDC * pDC) Line 382                C++

ToolkitPro1730vc140UD.dll!CXTPButton::OnPaint() Line 349                C++