Depending on the flow type of your service flow (Non Terminal, FEPI, Link3270 Bridge), only certain invoke types are supported. As specified in your Generation Properties, one of the invoke nodes in your Service Flow is of an invoke type that is not supported by the flow type of your flow (see About invoke types and About flow types).
Revise or remove from the flow any invoke node having an invoke type that is not supported by the flow type of the flow.