Steps reproduces

• Prepare a file with this name (non-latin characters): 金魚 きんぎょ キンギョ kingyo goldfish.png
• Create a page and attach this file to this page
• View page and click on this file

Actual:

• => it redirects to Confluence home

Expected:

• It show content of this file or download this file

Notes

• Copy then Paste and Go this URL on url address
  have same result