Why does Adobe Digital Editions 4.5 for Mac keep crashing?

I downloaded Adobe Digital Editions so I could read magazines from my library on my MacBook (OS Tahoe 26.6.2). I downloaded a magazine from BorrowBox and was able to read it fine last night. This evening, I downloaded another magazine, but when I double-click the URLLink.acsm file, Digital Editions opens and then immediately closes. Does anyone know how I can fix this?