import mlreportgen.ppt.*;
pre = Presentation('myPresentation.pptx');
     
dispatcher = MessageDispatcher.getTheDispatcher;
     dispatcher.Filter.DebugMessagesPass = true;
l = addlistener(dispatcher,'Message', ...
      @(src,evtdata) disp(evtdata.Message.formatAsText));
     
dispatch(dispatcher,ErrorMessage('invalid slide',pre));
open(pre);
     
titleText = Text('This is a Title');
titleText.Style = {Bold};

replace(pre,'Title',titleText);
     
close(pre);
     
delete(l);