Arabic Support

To open and search in a PDf, you need Adobe Reader/Adobe Acrobat.

If you want to view an ePub file, then you need to use Adobe Digital Edition ADE. To answer your question, ADE is a viewer, so if your content is in the Arabic Language and it is not showing properly or cannot be searched, this is related to the authoring program that created the ePub in the first place. To be sure the problem is not from ADE, just use another ePub reader such as Apple Books, or the one from Google, just search for free ones out there for testing.