Blank PDF when viewed with IOS

I have updated our PDF Creator to the new one, but now when we send by email the PDF to a customer and receives in a Apple Phone, they cannot open and a blank document appears.

Have you any idea?
Setup is the defaut.



are you using AES encryption? native iOS viewers don't handle this properly, especially AES256.

Best regards


We use the default protection.
How can I make not to use AES protection?