Outlook crashing when opening pdf attachment

Some of my users are having issues when opening pdf attachments in Outlook 2013. It does not occur with all pdf attachments, it is just random. Users are on Windows 10 64 bit machines, using 32 bit Office 2013. I've uninstalled Adobe, reinstalled it, repaired it, same with Office. I've run diagnostics tools for Outlook, and disabled add-ons, I've tried to delete the temp outlook files, but it just stops responding and won't delete a single pdf file that is there. There are no issues when running Outlook in safe mode and can open the pdf attachment through OWA. The system and acrobat are up to date.