POST FlowObjectives with INVALID operation/Type/Flag type causes NPE

Using Rest API , POST a FlowObjectives with Invalid Operations/Flags TYPE throws a NPE java.lang.NullPointerException
Since the FlowObjectives Type is not valid the method decode in (ForwardObjectivesCodec.java) logs a warning and return NULL .
This is accessed by the FlowWebResource causing a NPE and returning a 500 response.