You will only receive this particular error message if you open the file within ADE. Otherwise if you simply try to open the file itself it may just ask you what software to open the file in, or it may simply open it in TextEdit (Mac), Notepad, or Wordpad (Windows).

This error message is caused by a bug in some web browsers when downloading the URLLink.acsm file where the file extension is removed. Then when you try to open the file in Adobe Digital Editions (ADE) the software does not recognise the file as a supported format.

In order to fix this you simply need to add the file extension (.acsm) back on to the file. Although if file extensions are hidden on your computer you may need to make them visible first.

For Mac

• To make file extensions visible:
• Open Finder and click on Preferences
• Click on the Advanced tab
• Check the box titled "Show all filename extensions", then exit out of Finder

To rename the URLLink file:

• Navigate to the place where you have downloaded the URLLink file
• Double click on the URLLink file
• Move your cursor to the end of the file name and simply add .acsm to the end of the file name and press Enter

For Windows

To make file extensions visible:

• Open the File Explorer by clicking on the folder icon on your taskbar, or by going to Start/Windows > Documents
• In the menu bar click on View, then Options
• In the options go to the View tab
• Uncheck the box titled "Hide extensions for known file types" then click OK

To rename the URLLink file:

• Navigate to the place where you have downloaded the URLLink file
• Now right click on the URLLink file, then click Rename
• Move your cursor to the end of the file name and simply add .acsm to the end of the file name and press Enter

Now if you try to open the file again it should be recognised as an acsm file and should open correctly in ADE.

Because this issue can involve opening the file in unsupported software, it is possible it could be confused with a different, similar issue where the .acsm file is associated with the wrong software, so it simply opens in unsupported software by default. For more information on that issue please see Error message: Adobe Reader could not open 'URLLink.acsm' because it is either not a supported file type or because the file has been damaged.

If you are still having difficulty opening the file in ADE please contact our support team. Please quote the error message when doing so.