I can't open acsm files on my Mac.

I downloaded a book from NetGalley but it just downloads a tiny acsm file. When I try to open the file, Adobe Digital Editions says "Unable to download Error getting License. License Server Communication Problem: E_ACT_NOT_READY." I found instructions online that say to deauthorize Adobe Digital Editions (https://community.adobe.com/t5/digital-editions-discussions/quot-error-getting-license-license-server-communication-problem-e-act-not-ready-quot/td-p/7981736)

but at step 3 Digitl Editions says "Unable to erase authorization. Please try again after some time."