We are able to create new books however when we add a new page - it gives us the "error writing to database" screen and hitting continue then bumps us back to main screen. The new page however is there when we go back into the book on the course webpage. As you can imagine this is very frustrating and time consuming. We appear to be able to make edits to the page and these save ok and the data is held.
The other issue involves making edits to the book settings page - originally we thought it might have just be affecting the book templates we had created before the change to 2.3. Unfortunately it appears to affect all (new and old). If you go back and make any changes to the settings page - you get the "error writing to database" screen when you save.