Why can't I enter a dining reservation in my touring plan which will overlap the closing time of the park?

Our plans will stop you from setting the end time after the closing time for the park. Luckily, there are easy ways around this, two of them in fact: you can either 1) remove the restaurant from the plan, knowing that you'll be going there when the park closes or, 2) change the dining step to 9:00pm so that the plan will automatically end at Sci-Fi. Then your plan will work just fine.