Converting ACSM files: Common Adobe Errors and Solutions

Converting ACSM files is no simple matter and unfortunately errors may happen.

Some of these errors are caused by misusing another tool when trying to open your ACSM file, such as Adobe Digital Editions.

Additionally, there are many providers out there -, OverDrive, CloudLibrary, Google Play, Kobo, etc, and each of them may behave a little bit differently and impose some limitations that could cause errors.

We try our best to handle everything for you when we convert your ACSM file, but not everything is always within our control. The good news? You may be able to fix the issue yourself!

To help you do so, we’ve gathered information about some of the more common errors that you may encounter when handling ACSM files.


This error indicates that the same ACSM file has already been converted or opened (fulfilled) at least once. “By another user” means that a different user other than the current one was used during the process.

Here are some possible solutions:

Solution #1: Deauthorize Adobe Digital Editions

If you used Adobe Digital Editions to open the same ACSM file before using our online conversion tool, you must deauthorize Adobe Digital Editions. Check out Adobe’s website on how to get it done.

Summary of actions:

  1. Open Adobe Digital Editions
  2. Make sure you’re logged in with the same user that you previously used to open the ACSM file.
  3. Go to Help → Erase Authorization

Solution #2: Deauthorize OverDrive

Similarly to Adobe Digital Editions, if you previously opened the ACSM file in the OverDrive app, deauthorize the OverDrive app. Check out their website for more info.

Summary of actions:

  1. Go the OverDrive app’s settings
  2. Find and select the option to deauthorize the app

Solution #3: Get a New Unfulfilled ACSM File

In some rare cases, downloading a new ACSM file can solve the issue. This depends on whether your content provider will consider this download new or not. For example, if you use a new user to download from, the website will recognize you as a new user and provide a new unfulfilled ACSM file.

Solution #4: Contact Support

Some of us may not have access to the device where their ACSM file was last opened. In that case, or if no other option worked out for you, our best advice is to contact your content provider’s support (e.g., Kobo, Google, OverDrive, etc), and kindly ask them to reset the authorization for your current books.


This error is exclusive to Google Play users and it means that you’ve already opened this ACSM file on too many devices (according to Google’s imposed limit).

Unfortunately there are only a couple of options to try:

Solution #1: Deauthorize Devices

As mentioned in the previous section, if you’ve used Adobe Digital Editions, OverDrive app or other software that opens the ACSM file and requires signup, try to deauthorize from one of them and see if it solves your case.

Solution #2: Contact Google Support

There’s not a lot of useful information about this error out there, but many users have reported that this method solved their issue.

You’ll need to contact Google Support and describe your issue. Follow the advice given by other users who encountered the same error.


An ACSM file contains information about its expiration date which is later used by the content provider during the validation process.

Usually, this error either means that too much time has passed since you downloaded the file, or that you’ve misconfigured time and date on your device (in case you installed a software like Adobe Digital Editions).

Your best option is to download a new ACSM file - This usually solves the issue.


This error means that the provider (e.g. Google, Kobo, etc) is having an unknown issue on their end.

Sometimes this is a very temporary issue, and retrying the conversion immaditaley might work. If the issue persists, however, it could take up to a few days before the content provider fixes things on their end. Our best suggestion in this case is to reach out to your content provider and let them know that you're seeing this error ('E_LIC_LICENSE_SIGN_ERROR').