Known issues with rendering EPUB 3 content:

On Windows, EPUB 3 features do not render if the IE version is less than 10.

On Windows, MathML feature is not supported.

On Windows, Detail, Bdi, Wbr tags are not supported.

On Windows, Add Note option is not supported.

On Windows, Mouse wheel scrolling is not supported.

Hitting Tab inside the contents of the book changes the content alignment.

You can only search forward, and within a chapter.

Other known issues:

Adobe Digital Editions will not turn to the next page automatically in the NVDA Say All mode. NVDA only reads the current page until the user changes the page.

If you have a prior version of Adobe Digital Editions installed along with Adobe Digital Editions 4.0, uninstalling one of them will de-associate the EPUB and ASCM file types with the application. You’ll then need to manually associate file types (see your operating system’s instructions for associating file types).

If you unplug a device while it is in the process of authorizing, ADE may report the device is authorized when it isn’t. After restarting ADE, it will show the correct authorization state of the device.

Simultaneously adding *.ACSM files along with *.EPUB/*.PDF files into the same library on Mac OS X is not recommended. Some *.PDF/ *.EPUB books may not be added in this case.