Can you try the below mentioned steps?
1) Quit ADE if it is running.
2) Take backup/move the books from "My Digital Editions" folder in Documents folder to a different location.
3) Launch ADE
Thanks Dominic - ADE now stays running - the only book in the folder was the one with the ADE software entitled "Getting started with Adobe" . I now get a message in the bookshelf window telling me the book is missing. As per your instruction, I moved it from the folder (I placed it on my desktop). Should I now move it back to a folder (which one) and how should I go about adding other Epubs so that the program doesn't crash again?
I look forward to replies. I would like to start borrowing books from our local library and inturn read them on my KOBO.
So one of the downloaded book might be causing the crash. Now move the books back to the My Digital Edition folder.
In case if the crash occurs again, move the one by one to sort out the books causing the issue.
Hope this helps you.
Could you explain the last detail more please as it hasn't worked for me