The E_ADEPT_REQUEST_EXPIRED error can occur in the following situations:
- When you activate Adobe Digital Editions 1.x
- When you download and open EPUBs
You can sometimes get the following error message while activating Adobe Digital Editions:
E_ADEPT_REQUEST_EXPIRED http://adeactivate.adobe.com/adept/Activate
If any of the following system settings are incorrect, this error can occur:
- Clock time
- Date
- Time zone
Carefully check your device's system time, date, and time zone to verify that they are correct in relation to your location. You can access time settings by clicking or double-clicking your clock. In addition, check whether the daylight savings time feature is enabled for your time zone.

Adobe Digital Editions (ADE) uses ACSM files to download ebooks. When you purchase an eBook, you receive an ACSM file. You open the ACSM file in Adobe Digital Editions, and it then downloads the eBook. The ACSM contains an expiry time, and if you don't download the book within that token expiry time, you can't download the eBook.
To fix this issue, download the book again from your library website or bookstore. When you download the ACSM file, be sure to open it right away so you can download your selection without any errors.