Issue Summary

PDF preview does not render characters both multibyte characters and single-byte characters.
Some pdf files are not rendered on PDF Preview in 7.16.3.

This is reproducible on Data Center: yes

Steps to Reproduce

1. Attach the sample pdf file to a page. ( testpdf.pdf )
   
2. Save the page.
3. thumbnail looks good.
   
4. Preview the pdf file. no characters.
   

Expected Results

Characters are rendered normally.

Actual Results

All characters are not rendered in PDF preview.

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available