Summary

Attachments with the acute accent are not recognized in Confluence and being displayed as "Unknown Attachment" on the imported Space.

Steps to Replicate

1. Create a new Space on Confluence Server
2. Create a new page
3. Insert an attachment that has the accent on its name (i.e. Capture d’écran)
4. Export the space as XML
5. Import in other Confluence Server instance
6. Open the page with the attachment

Expected Behavior

The attachment would be display

Actual Behavior

The attachment is displayed as a block with "Unknown Attachment" inside

The page storage format for the "Unknown Attachment" shown as the following:

<ri:attachment ri:filename="Capture d&rsquo;écran 2017-09-19 à 17.28.57.png" /></ac:image><br />

Workaround

Re-attach the file, or rename and re-attach it to the page.
After reattach, the page storage format for the "Unknown Attachment" shown as the following:

<ri:attachment ri:filename="Capture d'écran 2017-09-19 à 17.28.57.png" /></ac:image><br />