Hi Andie
In this scenario I believe the Partner Determination Procedure for this Transaction has not been able to determine a single Partner to met the "Service Team" auto determination.
Take a look at the access sequence and see if based on the system set-up, a Service Team can be automatically determined.
Also set the Maximum Number of Partners for this Partner Function from 5 to 1.
The configuration you want to locate is "Define Partner Determination Procedure"
Hope this helps
Regards
Arden