We are running office 2016 with Reader DC 19.021.20058/61. Users are unable to use the email as attachment button more than 1 time within Reader. We have a few forms created with an embedded button to email a certain email address. It will randomly work for one user, then it will not work the next time. We have tried all of the basic troubleshooting (uninstalling and re-installing both Office and Adobe) does not matter if they open in browser or in Adobe. Same form or different form, even tried re-creating the same form to make sure it was not a version compatibility issue. Outlook is not Cached (we have tried both options) we do not have search on-line selected. Tried saving the default mail app and making users select it. Enhanced security and not enhanced security.
If it was AV it would not work for anyone, but we have also disabled AV to confirm this is not the issue.