crash after 10 undos

Hi there,

i tested fresco on two windows platforms, and on both the app crashes after exactly 10 undos. it's always after exactly 10 times undoing.

Tested on Microsoft Surface Pro 6 (Windows 10 Home, Version 21H1, Build 19043.1387, Intel Core i5-8250U, 8GB RAM)

and Thinkpad P53, (Windows 10 Pro, Version 21H1, Build 19043.1387, Intel Core i5-9400H 48GB RAM