YIKES I'm so sorry! I have to look into it and fix it up! I'm so sorry you experienced an error!
Basically it's a check if you helped Angelo by using your own abilities to turn the plant to stone earlier on in the game-- but I'm not sure why it's causing an error. You may be able to bypass it by using the skip option on the error screen. I figured out its because I seemingly defined the stupid thing in the wrong place so if you didn't help Angelo and tried to comfort him instead the game doesn't define it. I'm so, so sorry!! I'll add a fix in a bit for it, but you should be able to press 'continue' on the error screen instead.