Why do I get errors when viewing files on an Apple Mac?

The most recent files in the library are built using the official Acrobat writer to the international standard PDF 1.7 ISO 32000-1:2008 for maximum compatibility and portability.

Unfortunately Apple has chosen not to fully implement the ISO PDF standards in it's native document reader 'Preview' so some files may not be readable in this reader.

To view PDF 1.7 files it is recommended to install the latest version of the official free Acrobat reader from the Adobe website and use this program to open the downloaded files.