Don't use previous saves as was stated earlier and in the OP.....
start new game..... choose MC's name and then skip to chapter 6.
I looked 5 minutes in your game code and probably the only reason we have to start a new game is your shoddy coding.
In chapter 6 the MC can go to the beach and the first time you use the beach variable is on line 10092 (in chapter 6)
But you define the variable at game start on line 110 so now it is not in anyone's old save.
There is zero reason to define this variable at game start except to fuck up save games.
Instead you should have defined all new variables on lines 10006, you know below your ########### CHAPTER 06 ########### banners in the code.
This way old saves would keep on working as long as you did not make any serious edits to previous chapters where you introduced new variables.