SAP Message AQV441 - Field '&' not suitable for ranked list

Diagnosis
The ranking list you want cannot be generated.
When a ranking list is generated, a line of the ranking list isgenerated at a certain timepoint from the data that was read. Thistimepoint primarily depends on the ranking list criterium, but also onthe key fields (non-numeric fields). The field reported to be incorrectis not consistent with this timepoint, i.e. at this timepoint nomeaningful values can be determined for this field. There are two caseshere:
1. The field is a non-numeric field.
This field lies hierarchically in the logical database below theranking list criterium or parallel to the ranking list criterium.
2. The field is a numeric field.
This field lies hierarchically in the logical database above theranking list criteirum or parallel to the ranking list criterium.

Procedure
Entfernen Sie das fehlerhaft gemeldete Feld aus der Rangliste.