I have found problem with attached files in DC version (in XI or 7 it shows correctly). Language of files and diacretic signs - in Polish.
Filenames of attached files contain polish diacretic signs. Before attaching them - correct diacretic signs. After attaching - asian-like instead of polish. Text of main file is ok tho. Attachment list looks like that:

If I open any of those attachements - contents are fine. BUT if I edit main file in DC PRO while having those scrambled names in attachements - the whole main file will go bad also.
Problem is that if I open the same file in older viewer version (or even edit main file with older pro version and save - no problems there - it only concerns DC).
List of used fonts from main file:



If I open files from attachments list directly or save file and open (files will save with asian signs but will open) - files contents are OK.
Fonts used in attachments:
All files have only one font:

Main file with attachments is digitally signed, attachments are not individually digitally signed.

Once again - opening this file in older verisons give no problems, it only concerns DC.