Data Flow transformation shapes cannot be used in combination with the Compose or Merge shapes
Valid from Pega Version 7.1.8
When you reference another data flow from a data flow that contains the Compose or shape, the referenced data flow cannot contain transformation shapes (, , ).
Data flow validation does not currently prevent you from designing a data flow that goes against this design pattern. Make sure that your data flows follow this design pattern by checking the referenced and referencing data flows.