The fact that a plan has "N/A" listed instead of arrival times, wait times, etc. reflects some sort of impossibility. In some circumstances, this manifests itself as a ridiculously high wait time (say, more than 5000 minutes).
If you are using "Optimize," you will not likely see this unless you have substantially more attractions on your plan than can be completed in the day.
If you are using "Evaluate," you need to figure out what impossibility you created. Some things to look for:
- Are you visiting an attraction during a time when it is closed? Attractions that are open hours other than park hours should have their hours listed on the step.
- Do you have a show on your schedule that is only performed outside of the hours of you plan?
- Do you have attractions that require a pre-requisite? The most common example is that you need to ride Wildlife Express Train - Africa Station in Animal Kingdom in order to get to where you can experience the attractions in Rafiki's Planet Watch.
Once you mitigate the impossibility, your plan should optimize properly.
Note that using Evaluate can be tricky and time-consuming, especially if you are using FASTPASS or FastPass+ along with it. You can create impossible situations that we've never dreamed of, and we will not necessarily display an error message. When troubleshooting, think carefully about each step.