fix: increase DisconnectTimeout to 30s in release builds + building desync + client packet guards

- LiteNetLibServer/Client: set DisconnectTimeout=30000ms in release (was default 5000ms)
  Prevents false disconnects ~8s after initial sync completes when post-sync
  game loading briefly stalls LiteNetLib ping delivery.

- BuildingManager.UpdateBase: call NotifyPlayerDesync on ghost/base entity not
  found paths (previously dropped packet silently instead of warning client)

- BuildingDesyncWarningProcessor: reset LocalOperations=0 on desync warning so
  next build uses correct serverOp+1 operation ID

- BuildingHandler.InitializeOperations: only call ResetToId when tracker is
  behind, preventing stale join-time snapshot from clobbering a tracker already
  advanced by relayed packets during the sync wait window

- PlayerHeldItemChangedProcessor: guard against packet arriving before
  RemotePlayerInitialSyncProcessor runs (was throwing OptionalEmptyException)

- ToggleLightsProcessor: guard with TryGetObjectFrom instead of RequireObjectFrom
  (was throwing on missing object)

- Items.Dropped: null guard PrefabIdentifier.ClassId before use (was NullRef
  causing silent dropped-item desync)

Author: Jacqueb-1337

Nitrox.Server.Subnautica/Models/Communication/LiteNetLibServer.cs

@@ -64,9 +64,10 @@ public Task StartAsync(CancellationToken cancellationToken)
         server.UpdateTime = 15;
         server.UnsyncedEvents = true;
 #if DEBUG
-        server.DisconnectTimeout = 300000; //Disables Timeout (for 5 min) for debug purpose (like if you jump though the server code)
+        server.DisconnectTimeout = 300_000; //Disables Timeout (for 5 min) for debug purpose (like if you jump though the server code)
+#else
+        server.DisconnectTimeout = 30_000; // 30 seconds; prevents false disconnects when post-sync game-loading stalls LiteNetLib briefly
 #endif
-
         server.Start(options.Value.ServerPort);
         return Task.CompletedTask;
     }

Nitrox.Server.Subnautica/Models/GameLogic/Bases/BuildingManager.cs

@@ -167,12 +167,14 @@ public bool UpdateBase(Player player, UpdateBase updateBase, out int operationId
         if (!entityRegistry.TryGetEntityById<GhostEntity>(updateBase.FormerGhostId, out _))
         {
             logger.ZLogError($"Trying to place a base from a non-registered ghost (GhostId: {updateBase.FormerGhostId})");
+            NotifyPlayerDesync(player);
             operationId = -1;
             return false;
         }
         if (!entityRegistry.TryGetEntityById(updateBase.BaseId, out BuildEntity buildEntity))
         {
             logger.ZLogError($"Trying to update a non-registered build (BaseId: {updateBase.BaseId})");
+            NotifyPlayerDesync(player);
             operationId = -1;
             return false;
         }

NitroxClient/Communication/NetworkingLayer/LiteNetLib/LiteNetLibClient.cs

@@ -54,7 +54,9 @@ public LiteNetLibClient(PacketReceiver packetReceiver, INetworkDebugger networkD
             ChannelsCount = (byte)typeof(Packet.UdpChannelId).GetEnumValues().Length,
             IPv6Enabled = true,
 #if DEBUG
-            DisconnectTimeout = 300000 //Disables Timeout (for 5 min) for debug purpose (like if you jump though the server code)
+            DisconnectTimeout = 300_000, //Disables Timeout (for 5 min) for debug purpose (like if you jump though the server code)
+#else
+            DisconnectTimeout = 30_000, // 30 seconds; prevents false disconnects when post-sync game-loading stalls LiteNetLib briefly
 #endif
         };
     }

NitroxClient/Communication/Packets/Processors/BuildingDesyncWarningProcessor.cs

@@ -20,6 +20,7 @@ public Task Process(ClientProcessorContext context, BuildingDesyncWarning packet
         {
             OperationTracker tracker = BuildingHandler.Main.EnsureTracker(operation.Key);
             tracker.LastOperationId = operation.Value;
+            tracker.LocalOperations = 0;  // discard locally-queued ops, server's value is now authoritative
             tracker.FailedOperations++;
         }
 

NitroxClient/Communication/Packets/Processors/PlayerHeldItemChangedProcessor.cs

@@ -28,11 +28,15 @@ public PlayerHeldItemChangedProcessor(PlayerManager playerManager)
 
     public Task Process(ClientProcessorContext context, PlayerHeldItemChanged packet)
     {
-        Optional<RemotePlayer> opPlayer = playerManager.Find(packet.SessionId);
-        Validate.IsPresent(opPlayer);
+        if (!playerManager.TryFind(packet.SessionId, out RemotePlayer opPlayer))
+        {
+            Log.Warn($"[{nameof(PlayerHeldItemChangedProcessor)}] Could not find player with session id: {packet.SessionId}.");
+            return Task.CompletedTask;
+        }
 
         if (!NitroxEntity.TryGetObjectFrom(packet.ItemId, out GameObject item))
         {
+            Log.Warn($"[{nameof(PlayerHeldItemChangedProcessor)}] Could not find entity with id: {packet.ItemId}.");
             return Task.CompletedTask;
         }
 
@@ -41,15 +45,15 @@ public Task Process(ClientProcessorContext context, PlayerHeldItemChanged packet
 
         Validate.NotNull(pickupable.inventoryItem);
 
-        ItemsContainer inventory = opPlayer.Value.Inventory;
+        ItemsContainer inventory = opPlayer.Inventory;
         PlayerTool tool = item.GetComponent<PlayerTool>();
 
         // Copied from QuickSlots
         switch (packet.Type)
         {
             case PlayerHeldItemChanged.ChangeType.DRAW_AS_TOOL:
                 Validate.IsTrue(tool);
-                ModelPlug.PlugIntoSocket(tool, opPlayer.Value.ItemAttachPoint);
+                ModelPlug.PlugIntoSocket(tool, opPlayer.ItemAttachPoint);
                 Utils.SetLayerRecursively(item, viewModelLayer);
                 foreach (Animator componentsInChild in tool.GetComponentsInChildren<Animator>())
                 {
@@ -66,8 +70,8 @@ public Task Process(ClientProcessorContext context, PlayerHeldItemChanged packet
                 }
                 item.SetActive(true);
                 tool.SetHandIKTargetsEnabled(true);
-                SafeAnimator.SetBool(opPlayer.Value.ArmsController.GetComponent<Animator>(), $"holding_{tool.animToolName}", true);
-                opPlayer.Value.AnimationController["using_tool_first"] = packet.IsFirstTime != null;
+                SafeAnimator.SetBool(opPlayer.ArmsController.GetComponent<Animator>(), $"holding_{tool.animToolName}", true);
+                opPlayer.AnimationController["using_tool_first"] = packet.IsFirstTime != null;
 
                 if (item.TryGetComponent(out FPModel fpModelDraw)) //FPModel needs to be updated
                 {
@@ -93,8 +97,8 @@ public Task Process(ClientProcessorContext context, PlayerHeldItemChanged packet
                 {
                     componentsInChild.cullingMode = AnimatorCullingMode.CullUpdateTransforms;
                 }
-                SafeAnimator.SetBool(opPlayer.Value.ArmsController.GetComponent<Animator>(), $"holding_{tool.animToolName}", false);
-                opPlayer.Value.AnimationController["using_tool_first"] = false;
+                SafeAnimator.SetBool(opPlayer.ArmsController.GetComponent<Animator>(), $"holding_{tool.animToolName}", false);
+                opPlayer.AnimationController["using_tool_first"] = false;
 
                 if (item.TryGetComponent(out FPModel fpModelHolster)) //FPModel needs to be updated
                 {
@@ -104,7 +108,7 @@ public Task Process(ClientProcessorContext context, PlayerHeldItemChanged packet
                 break;
 
             case PlayerHeldItemChanged.ChangeType.DRAW_AS_ITEM:
-                pickupable.inventoryItem.item.Reparent(opPlayer.Value.ItemAttachPoint);
+                pickupable.inventoryItem.item.Reparent(opPlayer.ItemAttachPoint);
                 pickupable.inventoryItem.item.SetVisible(true);
                 Utils.SetLayerRecursively(pickupable.inventoryItem.item.gameObject, viewModelLayer);
                 break;

NitroxClient/Communication/Packets/Processors/ToggleLightsProcessor.cs

@@ -9,7 +9,11 @@ internal sealed class ToggleLightsProcessor : IClientPacketProcessor<Nitrox.Mode
 {
     public Task Process(ClientProcessorContext context, Nitrox.Model.Subnautica.Packets.ToggleLights packet)
     {
-        GameObject gameObject = NitroxEntity.RequireObjectFrom(packet.Id);
+        if (!NitroxEntity.TryGetObjectFrom(packet.Id, out GameObject gameObject))
+        {
+            Log.Warn($"[{nameof(ToggleLightsProcessor)}] Could not find entity with id: {packet.Id}.");
+            return Task.CompletedTask;
+        }
         ToggleLights toggleLights = gameObject.RequireComponent<ToggleLights>();
 
         if (packet.IsOn == toggleLights.GetLightsActive())

NitroxClient/GameLogic/Bases/BuildingHandler.cs

@@ -386,7 +386,15 @@ public void InitializeOperations(Dictionary<NitroxId, int> operations)
     {
         foreach (KeyValuePair<NitroxId, int> pair in operations)
         {
-            EnsureTracker(pair.Key).ResetToId(pair.Value);
+            OperationTracker tracker = EnsureTracker(pair.Key);
+            // Only reset if the server's snapshot is newer than what we already have.
+            // RegisterOperation() may have already advanced the tracker beyond this
+            // snapshot (e.g. UpdateBase packets received during the initial-sync wait),
+            // so overwriting with a stale value would immediately desync the client.
+            if (tracker.LastOperationId < pair.Value)
+            {
+                tracker.ResetToId(pair.Value);
+            }
         }
     }
 

NitroxClient/GameLogic/Items.cs

@@ -106,7 +106,13 @@ public void Dropped(GameObject gameObject, TechType? techType = null)
 
         NitroxId id = NitroxEntity.GetIdOrGenerateNew(gameObject);
         Optional<EntityMetadata> metadata = entityMetadataManager.Extract(gameObject);
-        string classId = gameObject.GetComponent<PrefabIdentifier>().ClassId;
+        PrefabIdentifier prefabIdentifier = gameObject.GetComponent<PrefabIdentifier>();
+        if (!prefabIdentifier)
+        {
+            Log.Error($"[{nameof(Items)}] Cannot sync dropped object '{gameObject.name}': missing PrefabIdentifier");
+            return;
+        }
+        string classId = prefabIdentifier.ClassId;
         int level = gameObject.TryGetComponent(out LargeWorldEntity largeWorldEntity) ? (int)largeWorldEntity.cellLevel : 0;
 
         WorldEntity droppedItem;