Campaign ironman issue

Hi guys! It’s the second time when my brother started the ironman campaign with someone and the game got saved with bug. Once it happened like after download and wanted to continue the game he didn’t got enemies and without enemies he couldn’t continue. So he started again and now he got a snacher which cannot die. If that snacher eat someone you cannot shout out from it because anything you do it’s like immortal. Can somebody fix this problem for my brother and than he can continue the game and don’t need to start again from the start because of bugs please? Thank you.