Non-ASCII characters are stripped from the Content-Disposition header response with map and feature service attachments in ArcGIS for Server 10.3. This causes the suggested file name to drop all non-ASCII characters when a user tries to save or download the attachment.
Duplicate of BUG-000083810 : This issue has been fixed in Server 10.3.1.
対処法
Workaround 1) Manually specify (re-type) the non-ASCII characters when saving the attachment.
Workaround 2) Do not utilize non-ASCII characters for attachment names.