Feature classes or tables that are used as starting points or barriers must include the FEATUREGLOBALID field to serve as valid trace locations. Certain versions of the utility network have different field requirements, which include SOURCEID and TERMINALID fields.
Ensure that the feature class or table has a FEATUREGLOBALID field of GUID type. If working with a version of the utility network that requires it, ensure that the feature class has a SOURCEID and TERMINALID field of Long Integer type. These fields must be present and populated with information from the associated network feature to be used as a trace location.