It is due to Ren'py changing the way they work.so I just tried to play the season 1 v1.0 and it seems like I am getting the incompatible saves issues. I was trying to look for a patch or something but I dont seem to see one. was there a fix for this? I noticed you mentioned it was due to the updated rpyn and you downgraded it to fix the issue, but is there a file to download where that can be done for the game?
You have 2 options, you can either keep trying your saves, and find one that is close to use, or start over, and hold down control and skip through the parts you saw, doesn't take that long in a game like this.