Makes a lot of entity systems unsubscribe from events on shutdown.

Content.Client/GameObjects/EntitySystems/ConstructionSystem.cs

@@ -51,8 +51,12 @@ namespace Content.Client.GameObjects.EntitySystems
         /// <inheritdoc />
         public override void Shutdown()
         {
-            CommandBinds.Unregister<ConstructionSystem>();
             base.Shutdown();
+
+            UnsubscribeLocalEvent<PlayerAttachSysMessage>();
+            UnsubscribeNetworkEvent<AckStructureConstructionMessage>();
+
+            CommandBinds.Unregister<ConstructionSystem>();
         }
 
         public event EventHandler<CraftingAvailabilityChangedArgs>? CraftingAvailabilityChanged;

Content.Client/GameObjects/EntitySystems/DoAfter/DoAfterSystem.cs

@@ -40,6 +40,12 @@ namespace Content.Client.GameObjects.EntitySystems.DoAfter
             SubscribeLocalEvent<PlayerAttachSysMessage>(HandlePlayerAttached);
         }
 
+        public override void Shutdown()
+        {
+            base.Shutdown();
+            UnsubscribeLocalEvent<PlayerAttachSysMessage>();
+        }
+
         private void HandlePlayerAttached(PlayerAttachSysMessage message)
         {
             _attachedEntity = message.AttachedEntity;

Content.Client/GameObjects/EntitySystems/HealthOverlay/HealthOverlaySystem.cs

@@ -46,6 +46,13 @@ namespace Content.Client.GameObjects.EntitySystems.HealthOverlay
             SubscribeLocalEvent<PlayerAttachSysMessage>(HandlePlayerAttached);
         }
 
+        public override void Shutdown()
+        {
+            base.Shutdown();
+
+            UnsubscribeLocalEvent<PlayerAttachSysMessage>();
+        }
+
         public void Reset()
         {
             foreach (var gui in _guis.Values)

Content.Client/GameObjects/EntitySystems/IconSmoothSystem.cs

@@ -24,9 +24,16 @@ namespace Content.Client.GameObjects.EntitySystems
         /// <inheritdoc />
         public override void Initialize()
         {
-            SubscribeLocalEvent<IconSmoothDirtyEvent>(HandleDirtyEvent);
+            base.Initialize();
 
-            IoCManager.InjectDependencies(this);
+            SubscribeLocalEvent<IconSmoothDirtyEvent>(HandleDirtyEvent);
+        }
+
+        public override void Shutdown()
+        {
+            base.Shutdown();
+
+            UnsubscribeLocalEvent<IconSmoothDirtyEvent>();
         }
 
         public override void FrameUpdate(float frameTime)

Content.Client/GameObjects/EntitySystems/VerbSystem.cs

@@ -46,7 +46,6 @@ namespace Content.Client.GameObjects.EntitySystems
         public override void Initialize()
         {
             base.Initialize();
-            IoCManager.InjectDependencies(this);
 
             SubscribeNetworkEvent<VerbSystemMessages.VerbsResponseMessage>(FillEntityPopup);
             SubscribeNetworkEvent<PlayerContainerVisibilityMessage>(HandleContainerVisibilityMessage);
@@ -62,11 +61,14 @@ namespace Content.Client.GameObjects.EntitySystems
 
         public override void Shutdown()
         {
+            base.Shutdown();
+
+            UnsubscribeNetworkEvent<VerbSystemMessages.VerbsResponseMessage>();
+            UnsubscribeNetworkEvent<PlayerContainerVisibilityMessage>();
             UnsubscribeLocalEvent<MoveEvent>();
             _contextMenuPresenter?.Dispose();
 
             CommandBinds.Unregister<VerbSystem>();
-            base.Shutdown();
         }
 
         public void Reset()

Content.Client/GameObjects/EntitySystems/WindowSystem.cs

@@ -17,6 +17,13 @@ namespace Content.Client.GameObjects.EntitySystems
             SubscribeLocalEvent<WindowSmoothDirtyEvent>(HandleDirtyEvent);
         }
 
+        public override void Shutdown()
+        {
+            base.Shutdown();
+
+            UnsubscribeLocalEvent<WindowSmoothDirtyEvent>();
+        }
+
         private void HandleDirtyEvent(WindowSmoothDirtyEvent ev)
         {
             if (ev.Sender.HasComponent<WindowComponent>())

Content.IntegrationTests/Tests/Networking/SimplePredictReconcileTest.cs

@@ -454,6 +454,13 @@ namespace Content.IntegrationTests.Tests.Networking
                 SubscribeLocalEvent<SetFooMessage>(HandleMessage);
             }
 
+            public override void Shutdown()
+            {
+                base.Shutdown();
+                UnsubscribeNetworkEvent<SetFooMessage>();
+                UnsubscribeLocalEvent<SetFooMessage>();
+            }
+
             private void HandleMessage(SetFooMessage message, EntitySessionEventArgs args)
             {
                 var entity = EntityManager.GetEntity(message.Uid);

Content.Server/GameObjects/EntitySystems/AI/AiSystem.cs

@@ -45,6 +45,13 @@ namespace Content.Server.GameObjects.EntitySystems.AI
             SubscribeLocalEvent<MobStateChangedMessage>(MobStateChanged);
         }
 
+        public override void Shutdown()
+        {
+            base.Shutdown();
+            UnsubscribeLocalEvent<SleepAiMessage>();
+            UnsubscribeLocalEvent<MobStateChangedMessage>();
+        }
+
         /// <inheritdoc />
         public override void Update(float frameTime)
         {

Content.Server/GameObjects/EntitySystems/AI/Pathfinding/Accessible/AiReachableSystem.cs

@@ -90,6 +90,22 @@ namespace Content.Server.GameObjects.EntitySystems.AI.Pathfinding.Accessible
             _mapManager.OnGridRemoved += GridRemoved;
         }
 
+        public override void Shutdown()
+        {
+            base.Shutdown();
+
+            _queuedUpdates.Clear();
+            _regions.Clear();
+            _cachedAccessible.Clear();
+            _queuedCacheDeletions.Clear();
+
+            _mapManager.OnGridRemoved -= GridRemoved;
+
+            UnsubscribeLocalEvent<PathfindingChunkUpdateMessage>();
+            UnsubscribeNetworkEvent<SharedAiDebug.SubscribeReachableMessage>();
+            UnsubscribeNetworkEvent<SharedAiDebug.UnsubscribeReachableMessage>();
+        }
+
         private void GridRemoved(MapId mapId, GridId gridId)
         {
             _regions.Remove(gridId);
@@ -126,20 +142,6 @@ namespace Content.Server.GameObjects.EntitySystems.AI.Pathfinding.Accessible
             _queuedCacheDeletions.Clear();
         }
 
-        public override void Shutdown()
-        {
-            base.Shutdown();
-            _queuedUpdates.Clear();
-            _regions.Clear();
-            _cachedAccessible.Clear();
-            _queuedCacheDeletions.Clear();
-            _mapManager.OnGridRemoved -= GridRemoved;
-            UnsubscribeLocalEvent<PathfindingChunkUpdateMessage>();
-            UnsubscribeLocalEvent<PlayerAttachSystemMessage>();
-            UnsubscribeNetworkEvent<SharedAiDebug.SubscribeReachableMessage>();
-            UnsubscribeNetworkEvent<SharedAiDebug.UnsubscribeReachableMessage>();
-        }
-
 #if DEBUG
         private void HandleSubscription(SharedAiDebug.SubscribeReachableMessage message, EntitySessionEventArgs eventArgs)
         {

Content.Server/GameObjects/EntitySystems/Body/Surgery/SurgeryToolSystem.cs

@@ -22,6 +22,14 @@ namespace Content.Server.GameObjects.EntitySystems.Body.Surgery
             SubscribeLocalEvent<SurgeryWindowCloseMessage>(OnSurgeryWindowClose);
         }
 
+        public override void Shutdown()
+        {
+            base.Shutdown();
+
+            UnsubscribeLocalEvent<SurgeryWindowOpenMessage>();
+            UnsubscribeLocalEvent<SurgeryWindowCloseMessage>();
+        }
+
         public void Reset()
         {
             _openSurgeryUIs.Clear();

Content.Server/GameObjects/EntitySystems/BuckleSystem.cs

@@ -27,6 +27,17 @@ namespace Content.Server.GameObjects.EntitySystems
             SubscribeLocalEvent<BuckleComponent, AttackHandMessage>(HandleAttackHand);
         }
 
+        public override void Shutdown()
+        {
+            base.Shutdown();
+
+            UnsubscribeLocalEvent<MoveEvent>();
+            UnsubscribeLocalEvent<EntInsertedIntoContainerMessage>();
+            UnsubscribeLocalEvent<EntRemovedFromContainerMessage>();
+
+            UnsubscribeLocalEvent<BuckleComponent, AttackHandMessage>(HandleAttackHand);
+        }
+
         private void HandleAttackHand(EntityUid uid, BuckleComponent component, AttackHandMessage args)
         {
             args.Handled = component.TryUnbuckle(args.User);
@@ -40,14 +51,6 @@ namespace Content.Server.GameObjects.EntitySystems
             }
         }
 
-        public override void Shutdown()
-        {
-            base.Shutdown();
-
-            UnsubscribeLocalEvent<MoveEvent>();
-            UnsubscribeLocalEvent<BuckleComponent, AttackHandMessage>(HandleAttackHand);
-        }
-
         private void MoveEvent(MoveEvent ev)
         {
             if (!ev.Sender.TryGetComponent(out BuckleComponent? buckle))

Content.Server/GameObjects/EntitySystems/GhostRoleSystem.cs

@@ -30,9 +30,18 @@ namespace Content.Server.GameObjects.EntitySystems
 
         public override void Initialize()
         {
+            base.Initialize();
+
             SubscribeLocalEvent<PlayerAttachSystemMessage>(OnPlayerAttached);
         }
 
+        public override void Shutdown()
+        {
+            base.Shutdown();
+
+            UnsubscribeLocalEvent<PlayerAttachSystemMessage>();
+        }
+
         private uint GetNextRoleIdentifier()
         {
             return unchecked(_nextRoleIdentifier++);

Content.Server/GameObjects/EntitySystems/HandsSystem.cs

@@ -51,8 +51,12 @@ namespace Content.Server.GameObjects.EntitySystems
         /// <inheritdoc />
         public override void Shutdown()
         {
-            CommandBinds.Unregister<HandsSystem>();
             base.Shutdown();
+
+            UnsubscribeLocalEvent<EntRemovedFromContainerMessage>();
+            UnsubscribeLocalEvent<EntInsertedIntoContainerMessage>();
+
+            CommandBinds.Unregister<HandsSystem>();
         }
 
         private static void HandleContainerModified(ContainerModifiedMessage args)

Content.Server/GameObjects/EntitySystems/StorageSystem.cs

@@ -16,10 +16,20 @@ namespace Content.Server.GameObjects.EntitySystems
         /// <inheritdoc />
         public override void Initialize()
         {
+            base.Initialize();
+
             SubscribeLocalEvent<EntRemovedFromContainerMessage>(HandleEntityRemovedFromContainer);
             SubscribeLocalEvent<EntInsertedIntoContainerMessage>(HandleEntityInsertedIntoContainer);
         }
 
+        public override void Shutdown()
+        {
+            base.Shutdown();
+
+            UnsubscribeLocalEvent<EntRemovedFromContainerMessage>();
+            UnsubscribeLocalEvent<EntInsertedIntoContainerMessage>();
+        }
+
         /// <inheritdoc />
         public override void Update(float frameTime)
         {

Content.Server/GameObjects/EntitySystems/WeightlessSystem.cs

@@ -26,6 +26,14 @@ namespace Content.Server.GameObjects.EntitySystems
             SubscribeLocalEvent<EntParentChangedMessage>(EntParentChanged);
         }
 
+        public override void Shutdown()
+        {
+            base.Shutdown();
+
+            UnsubscribeLocalEvent<GravityChangedMessage>();
+            UnsubscribeLocalEvent<EntParentChangedMessage>();
+        }
+
         public void Reset()
         {
             _alerts.Clear();