Have a client that is running both reader DC and pro 2017 in their citrix environment. So far when a user defaults thier PDF to DC they get WerFault.exe - Application Error. I defaulted them to use Acrobat Pro 2017 and they were able to open PDFs. Waiting for more feedback on what application other users are opening PDF's with. Years ago (Pre DC) I would normally install one or the other. Anyone know if it is best to install one or the other?