There were bug reports on Steam, related to the animals near Thelyron's house: two sheeps and one cow.
http://steamcommunity.com/app/373420/discussions/0/357284767254411522/It seems this bug occurs more often or only in modded games:
It was reported for Baardvaark's '6 party mod', Fumihiko's 'StatRebalanceV2' and, as I recently noticed, it also occurs in my 'BetterLogistics' mod. But it doesn't occur in Sniper's 'Four Character Creation', as far as I know (and see from a test).
I've looked into the dialogs of these animals and noticed an unchecked 'end dialog' box. And that's what caused the crash when trying to end the dialog. Checking the box fixed the problem. (CYS_Cow01, CYS_Sheep01, CYS_Sheep02)
But actually this should happen for all games, but it doesn't. Why is that?