Add missing isNpc() check (bug #5206)

CHANGELOG.md

@@ -172,6 +172,7 @@
     Bug #5186: Equipped item enchantments don't affect creatures
     Bug #5190: On-strike enchantments can be applied to and used with non-projectile ranged weapons
     Bug #5196: Dwarven ghosts do not use idle animations
+    Bug #5206: A "class does not have NPC stats" error when player's follower kills an enemy with damage spell
     Feature #1774: Handle AvoidNode
     Feature #2229: Improve pathfinding AI
     Feature #3025: Analogue gamepad movement controls

apps/openmw/mwmechanics/actors.cpp

@@ -1017,7 +1017,7 @@ namespace MWMechanics
                     {
                         if (caster == player || playerFollowers.find(caster) != playerFollowers.end())
                         {
-                            if (caster.getClass().getNpcStats(caster).isWerewolf())
+                            if (caster.getClass().isNpc() && caster.getClass().getNpcStats(caster).isWerewolf())
                                 caster.getClass().getNpcStats(caster).addWerewolfKill();
 
                             MWBase::Environment::get().getMechanicsManager()->actorKilled(ptr, player);