Thanks for the response.
I've replaced the EliMz Book plugin - can confirm it is 5.4.17
I'm using RPGMaker MZ 1.9.0
It's still giving me the same errors. What is odd is if I create a new MZ project and put both of your plugs in it will work fine. My project was an MV project I converted to MZ so maybe there's an issue there. Here is an expanded view of the book error. It's asking for a rendering engine. Any advice?