Parameter is not valid. while converting word to images

I met a exception while converting word to images.


The files what occurs exception, has almost close to 1,000 pages.
And when I open it with MS Word 2013, looks like working well.
but while scrolling pages, I met a message alert like below. (attached image)
'There are too many spelling or grammatical errors in ‘{fileName}’ to continue displaying them. To check the spelling and grammar of this document, choose Spelling and Grammar from the Review tab.'

Environment
Aspose.Word dll version: 15.2.0.0
OS: Windows 8 / 2008
.Net: 4.5

My code works for each pages.
1. Create Document instance.
2. loop pages
3. document.Save({stream}, option); // option’s PageIndex is current seq.
4. When reach to near 400 page, I met a ArgumentException.
- It is resemble to experience of MS word.

My code
private IEnumerable Convert(Document document, int pageCount, ConvertOption option)
{
var range = GetPageRanges(pageCount, option);
var imageOption = GetImageQuality(option.ConvertQuality);

// Save each page of the document as Png.
foreach (var seq in range)
{
using (LogHelper.Instance.GetTracer())
{
//string target = GetTargetFile(option, seq);
Stream stream = new MemoryStream();
imageOption.PageIndex = seq;
try
{
document.Save(stream, imageOption);
}
catch (Exception ex)
{
LogHelper.Instance.WriteException(LOG_TITLE, ex.Message, null, ex);
}
yield return new ConvertResult(seq, stream);
}
}
}

Hi Ethan,

Can you please share your input document to reproduce the issue?

Best Regards,