Confluence vs Companion App vs 2FA

[Matthias R]

Hi there,

I have a problem with Confluence 7.19.7 and editing documents via Companion App.

Confluence is configured to use SSO with 2FA.

When I view e.g. example.docx in confluence and click "Edit",
companion App starts and says, that it downloaded the document.
Word starts and reports an error, that it cannot read the file downloaded.

When I look in %userfolder%/.atlassian-companion, i see the file downloaded.

But when I open "example.docx" with a text editor, I see, that it only contains the HTML elements of the 2FA - welcome page.

Is this a bug, or may be there a mistake in Confluence's configuration?