You get a popup with messages in ME2xN/ME5xN and in the CHECK-Badi you have set flag to failed. But: you don’t want the popup anymore.
DATA lo_handle TYPE REF TO cl_message_handler_mm.
cl_message_handler_mm=>get_handler( IMPORTING ex_handler = lo_handle ).
Of course you can also do it more gentle by removing per event.
Or add your own 😉