@Sonnyof42 A bit more info: I tried putting Form1116ScheduleB.pdf in /Users/(my username)/Documents/attachment and in /Users/(my username)/attachment and in /Users/attachment. None of those worked. On the Mac, the root directory is read only, even to Sudo commands in Terminal. So I've not been able to create /attachment to try it there. If there is a secret place to stash the /attachment/Form1116ScheduleB.pdf file on a Mac, I have not found it.
I have a Windows virtual machine, so I suppose I can see if I can download a copy of the Windows version and see if it will open my Mac-created file. Then do the C:\attachment trick. That's a project for another day.
