This is exactly what I was looking for!
Every time I open a file to simply view it I'm asked to add it to the library.
The fact that I tick that check box to not being asked again simply doesn't work.
How to solve that problem?
This question is asked many times by many forum members, But no response from Adobe. They are careless as this product is a free One.
Check this thread.
I am using version 4.5.2. I found this option is temporary and only works when the app is active. Once it is closed, you will have to set the option again and cancel. This means that once you opened the app to view a non-library ebook, do not close the app and simply select the library icon to view your library. The dialog will appear and you simply set the do not copy option and cancel. As long as the app is not closed, the next time you double click on an ebook to view and back to the library, the annoying dialog will not appear. Hope this helps.