SAP Message BRAIN396 - Reference characteristic &1 is probably not suitable for &2

Diagnosis
In formula or key figure &V4&, aggregation &V2& is used with referencecharacteristic &V1&. The basic key figure going into &V4& is not anon-cumulative key figure, however.
The query now uses the finer time characteristic &V3&, or a timecharacteristic that cannot be derived from &V1&.
Formation of averages will therefore produce confusing results if &V3&is expanded.

Procedure
Check the query definition, in particular &V4&.