I create a new Task, but it won't let me set a reminder.

[Tasker]

Instead, I get a dialogue that says: The reminder for "Bring the form to
York Town Office" will not appear because the item isnot in your calendar or
Tasks folder. Is this OK?"

 

[Vince Averello [MVP-Outlook]]

Is it in some other folder than the defaults? If so, you'd need an addin to
get reminders to fire out of a non-default folder like the one here:
http://www.slovaktech.com/extendedreminders.htm