I've been trying hard, without success, to get Sigil1.2.0 to crash on Windows 10. So far I've tried epubs with both the traditional Sigil structure and non-standard structures. I've tried launching the epubs with Sigil using both Calibre's inherent "Open With" feature, and with the latest version of the third-party Calibre "Open With" plugin. I started with Calibre 4.6 and then moved to the latest Calibre 4.13.
No (non)joy so far.
Anyone with crashing issues care to share the output of:
(from a command prompt)?