Thanks for update, 
this time getting the same thing only as a warning. Not as error. Going to see if the packaged demo launches once packing is finished.
Edit: Actually now I have a theory why it gives that error/warning. Cooking only map content and there is no characters placed on level. So probably it looses the whole blueprint since its not packaged, since it dosent have a reference?
Edit2: My theory was wrong, still warning (even I have one character placed on level manually per pooled character). But going to see if the packaged Project launches.