On the RDA.APL 'ACTION PROCEDURE SERVICES' panel, can the user U (update) the action procedure which has been identified as invalid; '<== ACTION INVALID'?
Updating the action procedure, RAP235E will be displayed on the RDA.UBPM 'BUILD ACTION PROCEDURE' panel.
'Process Option ==>' will automatically be changed to 'U'.
Hitting enter should display the 'Model JCL Substitution' panel and perhaps another error message will be displayed pointing to the cause of the problem.