Applying Action Plans to Households and Contacts

[careyschwartzburt]

I click the “Create Contact Action Plan” button on a Household Detail page and I choose the Action Plan Template that I need to use for that Household. When I click “Save” I receive this error: "Invalid id: Error is in expression '{!save}' in component apex:page in page actionplancreation

An unexpected error has occurred. Your development organization has been notified."

How can I resolve this problem so I can add action plans to Households? Should I be applying APs a different way and, of so, how?

FYI The option to add an Action Plan does not appear for contacts.

Thank you very much for your help!