Fixes random NPEs (#378)

Projects/UOContent/Mobiles/Vendors/NPC/AnimalTrainer.cs

@@ -298,8 +298,11 @@ namespace Server.Mobiles
 
                 if (pet?.Deleted != false)
                 {
-                    pet.IsStabled = false;
-                    pet.StabledBy = null;
+                    if (pet != null)
+                    {
+                        pet.IsStabled = false;
+                        pet.StabledBy = null;
+                    }
                     from.Stabled.RemoveAt(i);
                     --i;
                     continue;

Projects/UOContent/Multis/Boats/Hold.cs

@@ -80,7 +80,7 @@ namespace Server.Items
         {
             if (m_Boat?.Contains(from) != true)
             {
-                m_Boat.TillerMan?.Say(502490); // You must be on the ship to open the hold.
+                m_Boat?.TillerMan?.Say(502490); // You must be on the ship to open the hold.
             }
             else if (m_Boat.IsMoving)
             {

Projects/UOContent/Spells/Bushido/LightningStrike.cs

@@ -18,10 +18,9 @@ namespace Server.Spells.Bushido
         public override bool Validate(Mobile from)
         {
             var isValid = base.Validate(from);
-            if (isValid)
+            if (isValid && from is PlayerMobile pm)
             {
-                var ThePlayer = from as PlayerMobile;
-                ThePlayer.ExecutesLightningStrike = BaseMana;
+                pm.ExecutesLightningStrike = BaseMana;
             }
 
             return isValid;
@@ -57,10 +56,10 @@ namespace Server.Spells.Bushido
 
         public override void OnClearMove(Mobile attacker)
         {
-            var
-                ThePlayer =
-                    attacker as PlayerMobile; // this can be deletet if the PlayerMobile parts are moved to Server.Mobile
-            ThePlayer.ExecutesLightningStrike = 0;
+            if (attacker is PlayerMobile pm)
+            {
+                pm.ExecutesLightningStrike = 0;
+            }
         }
     }
 }

Projects/UOContent/Spells/Fourth/FireField.cs

@@ -289,7 +289,11 @@ namespace Server.Spells.Fourth
 
                         while (m_Queue.Count > 0)
                         {
-                            var m = (Mobile)m_Queue.Dequeue();
+                            var m = m_Queue.Dequeue() as Mobile;
+                            if (m == null)
+                            {
+                                continue;
+                            }
 
                             if (SpellHelper.CanRevealCaster(m))
                             {

Projects/UOContent/Spells/Ninjitsu/ShadowJump.cs

@@ -39,9 +39,7 @@ namespace Server.Spells.Ninjitsu
             var from = Caster.Location;
             var to = new Point3D(p);
 
-            var pm = Caster as PlayerMobile; // IsStealthing should be moved to Server.Mobiles
-
-            if (!pm.IsStealthing)
+            if ((Caster as PlayerMobile)?.IsStealthing != true)
             {
                 Caster.SendLocalizedMessage(1063087); // You must be in stealth mode to use this ability.
             }