DOCX, XLSX and PPTX files are collections of conventionally zipped mostly XML sub-files. This program first attempts repair any zip based corruption. From there it engages in four different algorithmic attempts at repair or recovery.
With the first method using validation, the location of the first XML error is sought. At that point the sub-files are truncated and repaired. The second method works the same way except the XML validation is more lax. With the third, the strict XML validation...