SAP Message BRAIN378 - Formula element '&1 &2' cannot be input-ready

Diagnosis
A formula element can only be input ready if at least one precedingoperand is input ready, and an inverse formula has been defined for thisin Query Designer.
This is not the case for '&V1& &V2&'.

System Response
The input-readiness of '&V1& &V2&' will be retracted.

Procedure
If you do not think this should happen, check the query definition.