The selected file is not a valid binary Word 97-2003 document

[Spam Me]

By importing a docx file Confluence grumbles that it "is not a valid binary Word 97-2003 document", and it is right, it clearly a docx document. But actually Confluence supports docx files since version 3.1 (https://confluence.atlassian.com/confkb/error-appears-when-attempting-to-import-display-or-edit-microsoft-office-2007-documents-200213523.html) and the version of Confluence is 5.4.3.

The file upload doesn't work, here the link to a screenshot on an external picture hosting service:

https://image.ibb.co/b9Dd1F/Confluence.png

[Nic Brough -Adaptavist-]

Just because it says "docx" on the end does not mean it's of a docx type that can be read.  docx formats have a wide range of versions (and some of them are broken, not obeying their own standards)