This one might be specific to the file in question. I have an RTF file (called clean.rtf in the attachment) that I can open with Aspose.Words and save fine. If I first open a different document, and then open this RTF file and append it to the first document, the file size, section count, etc all seem to suggest that the document was successfully appended, but the pages in the RTF file are “missing” and the document structure seems to be broken.
Please see attached solution with unit test showing the behavior