Sometimes a "file association" error occurs on a Mac. What this means is that Adobe Digital Editions (ADE) is not set to open OverDrive files, and won't automatically open the ACSM file you downloaded. This error can be fixed with the steps found below.
Associate ACSM files to ADE on a Mac
- Locate the ACSM file, and Control-click on it.
- Click Get Info.
A file information window opens.
- Expand the Opens with section.
- Click the drop-down box, and select Adobe Digital Editions.
- Click Continue.
- Close the info window.
OverDrive eBooks will now automatically open with ADE.
If you're using Firefox, you may also need to change the file associations for the ACSM file in your browser.