SAP Message RMXMTRF048 - Selected master recipe phase &1 is the only phase

Diagnosis
You have tried to split a master recipe operation and to copy all phasesto the new master recipe operation, starting from the selected phaseV1.This is not possible because the selected phase is the only phase of thehigher-level operation &v2& that is always linked to the operation.

Procedure
Select a different master recipe phase.