D.E. hasn't worked for me for months. It continuously freezes when I import or try to open a book - double-clicking on a book does nothing and when I try to close the app down to restart I get "D.E is not responding. Shut down or wait?".
I've Googled the issue and it seems that others have experienced similar, but none of the recommended fixes have worked for me eg renaming my folder to "old" or reverting back to an older version (4.0). Prior to this problem, I've used D.E. without issue for a few years. Searching the other posts on this forum I see I am not the only one who is completely frustrated that I am forced to use this product because of DRM, but Adobe appears to be doing nothing to fix the issues.