Digital edition 4.5.10 as well 4.5.11 hangs despite authoring

Hello Team,

I am new to use DE. Recently installed version 4.5.10 in my Dell Laptop (Lattitude series), and whenever, I try to open the e-book File extension 'EPUB'), the application hangs and throws message in few seconds as 'Not Responding'. I don't have any option other than closing the application. I was asked to get an id from adobe site and authorise using the ID, which I did, still problem persisting for both 4.5.10 as well as 4.5.11.

I also tried uninstalling, restarting and reinstalling - nothing is helping. would appreciate if any one can help me to fix this issue