ERROR, element isn't supported
While cleaning an Office document made with Office 365, mat2 (latest version from master) has thrown these errors:
ERROR: In file /path/to/my/file.docx, element word/charts/chart1.xml's format (application/xml) isn't supported
ERROR: In file /path/to/my/file.docx, element word/media/image27.wmf's format (None) isn't supported
The .docx document is then not cleaned at all. I can't easily share the file in question unfortunately, but let me know if you want me to try a few things to debug if needed.