Fix index invalidation for effects.

Assets/Cryville/Crtr/Skin.cs

@@ -59,6 +59,7 @@ namespace Cryville.Crtr {
 			foreach (var e in effects) {
 				var effect = e.Value;
 				etor.ContextCascadeInsert();
+				etor.ContextCascadeUpdate(EffectInstance._VAR_INDEX, PropSrc.Error);
 				etor.Optimize(effect.duration);
 				effect.elements.Optimize(etor);
 				etor.ContextCascadeDiscard();