PDF/A Mode What does it do & how to disable it

[IAMTheBadWolf]

Removing PDF/A for editing. In Adobe Acrobat select Edit - Preferences - Under Categories column select Documents on the Right go down to PDF/A View Mode - in check box select - Never.

PDF/A is designed to give a minimal feature set to enable long term storage assuming that storage formats will vary in future rendering a full PDF document either partially or totally unreadable.

[Bill12]

Use Preflight in Acrobat to run the "Remove PDF /A information" script. I would work with a copy of your file.