In "ROMEEventLoop.cpp"
in function "ReadEvent(Int_t event)"
after "if (gROME->isOnline()&&gROME->isMidas()) {"

gROME should get serial_number and event ID from event header. 
There should be following 2 lines

  gROME->SetCurrentEventNumber(((EVENT_HEADER*)mEvent)->serial_number);
  gROME->SetEventID(((EVENT_HEADER*)mEvent)->event_id);