Just so you know what others have gathered over months ago:
Most RPGM games need player to SAVE ONCE IN ORDER TO CREATE THE ACTUAL WWW FOLDER FOR THE SAVES!
Also, RPGM EXE can be 1+GB long because the creation environment makes it possible to bottle a whole game up into EXE and those particular games may or may not create aggregate folders once you fire that 1+GB bad boy up.
I do believe that this game comes with www and save folder with 2 saves already.
If those steps do not work:
1-fire game up, play past the prologue and well into earning some coin and right click and make a save. Make several saves. Exit game and replace old saves over the ones you made anew. Should have same names coming from same game.
2-copy over whole save dir from older iteration of the game, where you have older global rpgmv files and it should work.
3-check if you have anything other than save dir inside WWW. If only save dir is in there, just copy whole WWW folder to game dir and replace the existing one.
All these might work but require trial and error - UNPACK GAME, TRY ONE STEP, if it don't work rinse and repeat.