I have a series of PDFs made with Indesign that are tagged. I'm cleaning them up and completed one that passes all checks (Acrobat, PAC and CommonLook) and yet will not pass a simple screen reader test. It never loads and reads as "blank."

This document came to me already tagged, but needed significant cleanup. However, it won't read at all even before I work on it, so I don't believe it's anything I'm doing.

I've tried various techniques none of which work:

• removing all the form fields
• removing graphics
• removing tags and retagging automatically
• saving as Word and remaking PDF with tags (even this did not work!)
• using Acrobat to create PDF from file -- this results in a "screen-readable" document but the text is scrambled and meaningless as if the document were encoded.

This file is using embedded Truetype (CID) fonts. The file was originally created in 2013 on a Mac. The other files in this set that do not have this problem were originally created in 2014.

I'm quite puzzled and cannot resolve this problem.