The following diagnostic is generating:

One or more of the Designation of Partnership Representative fields for the Designated Individual's Information is missing. Review the input for name, street address, city, state, zip code, and telephone number and ensure all fields are completed.

Solution:

On detail screen 3 ensure that all the fields (Name, Street Address, City, State, Zip Code and Phone Number) in one or both of the Designation of Partnership Representative fields are populated.