Issues with AltChunk

I managed to find the underlying problem to a rather annoying bug using AltChunk. I've generated thousands of reports using OpenXml but this one word document would always break xml markup of the document when inserting it using AltChunk.

After stripping the document to only contain the parts that broke it I managed to find out that the "DocumentSettingsPart" contained some elements called SmartTagType. I've never seen these before and not sure what they are used for but the moment I removed them from the document my AltChunk insertion started to work so I now remove them from all my documents before I insert using AltChunk.

I wonder if this is a known bug - will ask on the forum.

Here's some code:

// Get a list of smart tags in the document settings part and remove these
List<SmartTagType> smartTags = mainDocumentPart.DocumentSettingsPart.Settings.Descendants<SmartTagType>();

// Loop backwards otherwise the elements orders change
for (int i = smartTags.Count - 1; i >= 0; i--)
{
  smartTags[i].Remove();
}