diff --git a/Minecraft.Client/Chunk.cpp b/Minecraft.Client/Chunk.cpp
index 6f0ad736..0a63b874 100644
--- a/Minecraft.Client/Chunk.cpp
+++ b/Minecraft.Client/Chunk.cpp
@@ -739,9 +739,9 @@ void Chunk::rebuild_SPU()
 				{
 					// 4J - get tile from those copied into our local array in earlier optimisation
 					unsigned char tileId = pOutData->getTile(x,y,z);
-					if (tileId > 0)
+                    if (tileId > 0 && tileId != 0xff)
 					{
-						if (currentLayer == 0 && Tile::tiles[tileId]->isEntityTile())
+                        if (currentLayer == 0 && Tile::tiles[tileId] && Tile::tiles[tileId]->isEntityTile())
 						{
 							shared_ptr<TileEntity> et = region.getTileEntity(x, y, z);
 							if (TileEntityRenderDispatcher::instance->hasRenderer(et))
@@ -754,6 +754,7 @@ void Chunk::rebuild_SPU()
 						{
 
 							Tile *tile = Tile::tiles[tileId];
+							if (!tile) continue;
 							int renderLayer = tile->getRenderLayer();
 
 							if (renderLayer != currentLayer)
diff --git a/Minecraft.Client/PlayerConnection.cpp b/Minecraft.Client/PlayerConnection.cpp
index 8e056cd8..ee4d01bf 100644
--- a/Minecraft.Client/PlayerConnection.cpp
+++ b/Minecraft.Client/PlayerConnection.cpp
@@ -1588,6 +1588,10 @@ void PlayerConnection::handleCraftItem(shared_ptr<CraftItemPacket> packet)
 	if(iRecipe == -1)
 		return;
 
+	int recipeCount = (int)Recipes::getInstance()->getRecipies()->size();
+	if(iRecipe < 0 || iRecipe >= recipeCount)
+		return;
+
 	Recipy::INGREDIENTS_REQUIRED *pRecipeIngredientsRequired=Recipes::getInstance()->getRecipeIngredientsArray();
 	shared_ptr<ItemInstance> pTempItemInst=pRecipeIngredientsRequired[iRecipe].pRecipy->assemble(nullptr);
 
diff --git a/Minecraft.Client/ServerLevel.cpp b/Minecraft.Client/ServerLevel.cpp
index d322d9b6..a2596911 100644
--- a/Minecraft.Client/ServerLevel.cpp
+++ b/Minecraft.Client/ServerLevel.cpp
@@ -1077,7 +1077,12 @@ void ServerLevel::entityRemoved(shared_ptr<Entity> e)
 
 shared_ptr<Entity> ServerLevel::getEntity(int id)
 {
-	return entitiesById[id];
+    auto it = entitiesById.find(id);
+    if (it != entitiesById.end())
+    {
+        return it->second;
+    }
+    return nullptr;
 }
 
 bool ServerLevel::addGlobalEntity(shared_ptr<Entity> e)
diff --git a/Minecraft.Client/Windows64/Network/WinsockNetLayer.cpp b/Minecraft.Client/Windows64/Network/WinsockNetLayer.cpp
index e82118cd..28d29504 100644
--- a/Minecraft.Client/Windows64/Network/WinsockNetLayer.cpp
+++ b/Minecraft.Client/Windows64/Network/WinsockNetLayer.cpp
@@ -404,7 +404,7 @@ bool WinsockNetLayer::JoinGame(const char* ip, int port)
 
 bool WinsockNetLayer::SendOnSocket(SOCKET sock, const void* data, int dataSize)
 {
-	if (sock == INVALID_SOCKET || dataSize <= 0) return false;
+	if (sock == INVALID_SOCKET || dataSize <= 0 || dataSize > WIN64_NET_MAX_PACKET_SIZE) return false;
 
 	// TODO: s_sendLock is a single global lock for ALL sockets. If one client's
 	// send() blocks (TCP window full, slow WiFi), every other write thread stalls
diff --git a/Minecraft.World/AbstractContainerMenu.cpp b/Minecraft.World/AbstractContainerMenu.cpp
index 10d8afdc..c98fc22c 100644
--- a/Minecraft.World/AbstractContainerMenu.cpp
+++ b/Minecraft.World/AbstractContainerMenu.cpp
@@ -157,6 +157,9 @@ shared_ptr<ItemInstance> AbstractContainerMenu::clicked(int slotIndex, int butto
 	shared_ptr<ItemInstance> clickedEntity = nullptr;
 	shared_ptr<Inventory> inventory = player->inventory;
 
+	if (slotIndex < 0 || slotIndex >= (int)slots.size())
+		return nullptr;
+
 	if (clickType == CLICK_QUICK_CRAFT)
 	{
 		int expectedStatus = quickcraftStatus;
@@ -558,12 +561,13 @@ bool AbstractContainerMenu::isPauseScreen()
 
 void AbstractContainerMenu::setItem(unsigned int slot, shared_ptr<ItemInstance> item)
 {
+	if (slot >= slots.size()) return;
 	getSlot(slot)->set(item);
 }
 
 void AbstractContainerMenu::setAll(ItemInstanceArray *items)
 {
-	for (unsigned int i = 0; i < items->length; i++) 
+    for (unsigned int i = 0; i < items->length && i < slots.size(); i++) 
 	{
 		getSlot(i)->set( (*items)[i] );
 	}