Workaround for player: load any save made after loading the scene with that battle. Beware: enemy may tumble down onto any place (where they weren't)! I prefer to redo the battle from the very start (have a special save-slot allotted to the begin of a battle)
Can only guess, it might be both a general engine coding error and a mistake by a modder during creating the map in question (something like wrong rigged spawning points). Also can provide additional info:
- in AV it happened in G3!
- in VR it happened in K10 (with enemy tanks involved)!
NB obsolete AV 1.10 without ANY updates