Hello @JimH074 ,
If the error is occurring in the custom code editor itself, you may wish to reach out to our higher level technical team.
If the error is showing up on the scheduling page then it's either an issue of your physical address missing (which doesn't appear to be the case here), or you not having any active contacts / lists to select from. You need to have active contacts in lists in order to schedule / send a custom code email.