Thank you Lydia. That makes sense about the service packs as I can't currently connect to them as I am using CRM online 2015.
Regarding the missing tables. I thought I was missing the orders tables and orders products table but then realised that in the schema they are referred to as sales orders and sales orders details. I thought perhaps that Power BI only brought through a limited set but it does appear to be bringing all tables in.
Thank you.