PDF Viewer macro failed with PDF file version 1.6 and above

Steps to reproduce:

1. Upload HiAZ-Spiegel_150413.pdf to Confluence
2. Embedded it in Confluence page via Insert > PDF
3. Results: the PDF is not rendered

The same issue is also reported here: https://answers.atlassian.com/questions/63322/the-embedded-pdf-viewer-macro-view-file-doesn-t-work-in-confluence

Workaround:

Convert the PDF file to version 1.5 or below