Christmas Dungeon Bug 2

[ZalleWarriorPrincess]

I am in the middle of the dungeon and suddenly i cannot hurt any of the ice fiends after killing the others...So I have to leave because it will not die and then I'm stuck waiting forever. I can kill every other creature but any ice fiend that is the last one will not die..
I am using my Summon Avatar prayer.

Help?

*Edit: I can use fire spells to kill it but why does it stop working on my summon avatar or summon elemental?