Hello,
I am using a Mac running El Capitan 10.11.6 and this solution does not work for me. Quite frankly, after >30 years of using the Mac, I have never had to go to the Unix prompt to install an update for any software. This is a Endnote problem and needs to be fixed by Endnote, not through a work around like this. If this were an open source software package, I could understand the need to go to the Unix prompt to install some patches, but I expect much more from a piece of software that costs money. Every other application installer for the Mac will prompt for a password from the GUI, not from the Unix prompt.
Please fix this problem. This is a huge disappointment.