HI there
I am using version 4.5.6 on an iPhone 6S. I have downloaded a number of resources for offline use and am having a problem with some of them. For example I have the IVP historical books downloaded:

Upon opening the book the title shows correctly however no content loads, as shown below...

If I try to access the table of contents I am unable to do so, as it just remains loading...

Can anyone help me to browse my books off line please?
thanks
Paul