[KevinH]

Hmm, when you removed the ini file you should have removed all window positioning info. It should have then started on your first monitor as normal? Could you have an old copy of Sigil still running in the background someplace.

Perhaps windows has a screen affinity setting or stores info on app preferred starting screen someplace?

Perhaps try shutting down (not sleep) your computer and starting it up again with only one monitor connected would help? Then try connecting the other monitor.

Or temporarily set your monitors to mirror each other in an attempt to get control back?

I will dig up a second monitor and try this on my mac but I have never had crashing issues with Sigil before when using two monitors as macOS maps monitors into one large *contiguous* space but Windows can and does leave gaps (non-contiguous) if monitors do not have the same size and/or scale factors.