I have a Mail Merge template in which I am attempting to do an InsertHtml of a large "blob" of HTML. I get a NullReferenceException when doing this. I have attached a sample application where this is reproduced.
If you put a try/catch around the InsertHtml and ignore the exception the document seems to render correctly. I am not sure if the problem is because there is a large amount of data or if it is because there are unprintable characters in the document. In either case this same Html renders correctly in a browser.
Please do not respond saying we just need to clean up the data because I will just respond saying that we have no control over the content. This is our customers data, or application only does a Mail Merge of that data.