Near the start, Prince Thomas mentions the wedding dinner for 800 guests. The wedding set-up is clearly not set up for anything close to that number.
The stars Sirius and Vega are not close one to another as Izzy shows the prince. Both stars cannot be visible through the narrow viewpoint between tall buildings as shown in the movie.
When Thomas and Izzy are delivering goods to the school, they are in a left-hand drive truck on the left side of the road. It should be a right-hand drive vehicle.