Fixes crash with AreaTriggers

Source/Game/Entities/AreaTrigger/AreaTrigger.cs

@@ -1555,7 +1555,7 @@ namespace Game.Entities
         public override ObjectGuid GetOwnerGUID() { return GetCasterGuid(); }
         public ObjectGuid GetCasterGuid() { return m_areaTriggerData.Caster; }
 
-        public bool HasSplines() { return !_spline.Empty(); }
+        public bool HasSplines() { return _spline != null && !_spline.Empty(); }
         public Spline<float> GetSpline() { return _spline; }
 
         bool HasOrbit() { return m_areaTriggerData.PathData.Is<AreaTriggerOrbit>(); }

Source/Game/Entities/Object/Update/UpdateField.cs

@@ -353,15 +353,14 @@ namespace Game.Entities
         }
     }
 
-    public class VariantUpdateField(int blockBit, int bit, params Type[] types)
+    public class VariantUpdateField(int blockBit, int bit)
     {
         public object _value;
-        Type[] _types = types;
 
         public int BlockBit = blockBit;
         public int Bit = bit;
 
-        public bool Is<T>() { return _types.Contains(typeof(T)); }
+        public bool Is<T>() { return _value is T; }
 
         public T Get<T>() where T : class, new()
         {
@@ -466,7 +465,7 @@ namespace Game.Entities
 
         public void ClearChangesMask(VariantUpdateField field)
         {
-            if (typeof(IHasChangesMask).IsAssignableFrom(field._value.GetType()))
+            if (field._value != null && typeof(IHasChangesMask).IsAssignableFrom(field._value.GetType()))
                 ((IHasChangesMask)field._value).ClearChangesMask();
         }
 

Source/Game/Entities/Unit/Unit.cs

@@ -856,7 +856,7 @@ namespace Game.Entities
 
         public void RemoveAreaTrigger(AuraEffect aurEff)
         {
-            foreach (AreaTrigger areaTrigger in m_areaTrigger)
+            foreach (AreaTrigger areaTrigger in m_areaTrigger.ToList())
             {
                 if (areaTrigger.GetAuraEffect() == aurEff)
                 {
@@ -868,7 +868,7 @@ namespace Game.Entities
 
         public void RemoveAllAreaTriggers(AreaTriggerRemoveReason reason = AreaTriggerRemoveReason.Default)
         {
-            foreach (AreaTrigger at in m_areaTrigger)
+            foreach (AreaTrigger at in m_areaTrigger.ToList())
             {
                 if (reason == AreaTriggerRemoveReason.UnitDespawn && at.GetTemplate().ActionSetFlags.HasFlag(AreaTriggerActionSetFlag.DontDespawnWithCreator))
                     continue;