I was typing in Tincta (version 4.2), single open file, for about 40 minutes, about 95 lines of code. Plenty of memory. Not using any menus or special key combo, etc, just simply typing. Tincta became unresponsive and I had to force quit. I recall this happening before, so it happens occasionally. I am using an older system (Mac OS 10.11) so it may be related to that. Probably not relevant but the language selection was Haskell.