@berny that I'm afraid will remain unfixable. Not because I'm not able to fix it, but because it's impossible to fix.
I'll try to explain.
Every time I add a variable in the game it's being added in a file "main.rpy" which is read when you launch a new game. However, there are cases where this variables are written when you start a new game only (by clicking "New game" on the main screen) and if you load a previous savegame they are not recognized properly by the game and you receive an error.
I could only fix that in two ways:
- Declaring all the variables which I'll need in the game once and for all, which is impossible because the game is in development
- Declaring variables in new .rpy only, but that will create a mess in the code structure and I'm not used to work in messy development environments
So that's something you'll never get in the game as long as it remains in alpha stage. The best I've found for whoever doesn't want to try the updates because of the boring previously released content is over that post