IBooks book window shows no content

When I open a book from the iBooks Libary window, after the animated opening of the book I just get a transparent area on the screen were the book should be, see image below.

This appears to happen for all books, including any newly re-downloaded, and PDFs in the library. As well as when opening books directly from the finder.

This problem did not exist prior to upgrading to Sierra.

iBooks - version 1.6 (1240)