"Unable to download" error

How do I open an acsm file?

After installing the Digital Editions Download app (MacOS), I encounter a pop-up error message that simply says "Unable to Download"

Further, it states:

"Error getting License. License Server

Communication Problem:

ELLIC_ALREADY_FULFILLED_BY_AN-OTHER_USER"

I am the only user on this new machine that never had Adobe Digital Editions installed before.

Anyone can help with this error message? Thank you for your time and assistance in advance!