I see. In that case, it's a bug with the Glitch Script and nothing to do with your code/VN.
Thank you for the link, I'll send them a pull request to fix this issue.
As for the solution, look for this code:
theights = sorted(randomobj.randrange(cheight+1) for k in range(nslices)) # y coordinates demarcating all the strips
Then replace it with this:
theights = sorted(randomobj.randrange(int(cheight+1)) for k in range(nslices)) # y coordinates demarcating all the strips