After the upgrade to 5.3, there are some pdf files which are being rendered blank by the pdf macro.
This works without problems in a 5.2.5 version.
The attachment in this page can be used to reproduce the behavior.
Steps to reproduce.
1) Attach the pdf file of this ticket to a confluence page
2) Insert a pdf macro and load the pdf file
3) The macro will show a blank page and nothing more.
You can start confluence with `-Dpdf.render.memory.guard.disabled=true` system property in order to disable memory guard. That will make all pdfs to be rendered.
More information on how to set system properties in confluence can be found here
If the PDF doesn't render with the workaround in place, you must delete and recreate the PDF macro after placing the system property above and restarting Confluence.