I've been side-loading library eBooks on my Nook for a while now with no issues on my old PC. I just switched to a MacBook Air and am having serious issues trying to transfer library .epub files to my Nook. I downloaded an .ACSM file from OverDrive. When I double-click the file, ADE automatically launches and shows the cover and all the information for the book but won't let me do anything else with it. It crashes when I try to open the book through ADE or when I try to transfer it to my Nook with a USB cord. Please help!! I've tried older versions of ADE with the same problems. I've unauthorized and reauthorized my computer and Nook multiple times already. I don't know how to fix this.