diff --git a/composer.lock b/composer.lock
index a3eea84d6..26b239330 100644
--- a/composer.lock
+++ b/composer.lock
@@ -160,16 +160,16 @@
         },
         {
             "name": "pocketmine/nbt",
-            "version": "0.2.11",
+            "version": "0.2.12",
             "source": {
                 "type": "git",
                 "url": "https://github.com/pmmp/NBT.git",
-                "reference": "78784b93632c51f0fad0719b2d6ffe072529db6d"
+                "reference": "b5777265329753b74dd40bb105eedabeefb98724"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/pmmp/NBT/zipball/78784b93632c51f0fad0719b2d6ffe072529db6d",
-                "reference": "78784b93632c51f0fad0719b2d6ffe072529db6d",
+                "url": "https://api.github.com/repos/pmmp/NBT/zipball/b5777265329753b74dd40bb105eedabeefb98724",
+                "reference": "b5777265329753b74dd40bb105eedabeefb98724",
                 "shasum": ""
             },
             "require": {
@@ -194,10 +194,10 @@
             ],
             "description": "PHP library for working with Named Binary Tags",
             "support": {
-                "source": "https://github.com/pmmp/NBT/tree/0.2.11",
+                "source": "https://github.com/pmmp/NBT/tree/0.2",
                 "issues": "https://github.com/pmmp/NBT/issues"
             },
-            "time": "2019-10-21T14:50:43+00:00"
+            "time": "2019-12-01T08:20:26+00:00"
         },
         {
             "name": "pocketmine/raklib",
@@ -276,23 +276,20 @@
         },
         {
             "name": "pocketmine/spl",
-            "version": "0.3.2",
+            "version": "0.3.3",
             "source": {
                 "type": "git",
                 "url": "https://github.com/pmmp/SPL.git",
-                "reference": "7fd53857cd000491ba69e8db865792a024dd2c49"
+                "reference": "94d4df142fe837ba836e9348dd00209e4bdcc307"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/pmmp/SPL/zipball/7fd53857cd000491ba69e8db865792a024dd2c49",
-                "reference": "7fd53857cd000491ba69e8db865792a024dd2c49",
+                "url": "https://api.github.com/repos/pmmp/SPL/zipball/94d4df142fe837ba836e9348dd00209e4bdcc307",
+                "reference": "94d4df142fe837ba836e9348dd00209e4bdcc307",
                 "shasum": ""
             },
             "type": "library",
             "autoload": {
-                "exclude-from-classmap": [
-                    "stubs"
-                ],
                 "classmap": [
                     "./"
                 ]
@@ -302,9 +299,10 @@
             ],
             "description": "Standard library files required by PocketMine-MP and related projects",
             "support": {
-                "source": "https://github.com/pmmp/SPL/tree/master"
+                "source": "https://github.com/pmmp/SPL/tree/0.3.3",
+                "issues": "https://github.com/pmmp/SPL/issues"
             },
-            "time": "2018-08-12T15:17:39+00:00"
+            "time": "2019-10-28T11:41:20+00:00"
         }
     ],
     "packages-dev": [],
diff --git a/phpstan.neon b/phpstan.neon
index eeae576fe..e2d3ca6d5 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -1,7 +1,11 @@
-
+includes:
+	- tests/phpstan/configs/optional-com-dotnet.neon
+	- tests/phpstan/configs/optional-leveldb.neon
+	- tests/phpstan/configs/phpstan-bugs.neon
+	- tests/phpstan/configs/pthreads-bugs.neon
 
 parameters:
-	level: 1
+	level: 2
 	autoload_files:
 		- tests/phpstan/bootstrap.php
 		- src/pocketmine/PocketMine.php
@@ -57,22 +61,11 @@ parameters:
 			count: 1
 			path: src/pocketmine/network/mcpe/protocol/StartGamePacket.php
 
-		-
-			message: "#^Instantiated class COM not found\\.$#"
-			count: 2
-			path: src/pocketmine/network/upnp/UPnP.php
-			comment: "only available on Windows"
-
 		-
 			message: "#^Constructor of class pocketmine\\\\scheduler\\\\TaskScheduler has an unused parameter \\$logger\\.$#"
 			count: 1
 			path: src/pocketmine/scheduler/TaskScheduler.php
 
-		-
-			message: "#^Variable \\$GLOBALS in isset\\(\\) always exists and is not nullable\\.$#"
-			path: src/pocketmine/MemoryManager.php
-			comment: "this isn't defined on threads (thanks pthreads)"
-
 		-
 			message: "#^Constant pocketmine\\\\COMPOSER_AUTOLOADER_PATH not found\\.$#"
 			path: src/pocketmine
@@ -104,21 +97,9 @@ parameters:
 		-
 			message: "#^Constant pocketmine\\\\VERSION not found\\.$#"
 			path: src/pocketmine
+
 		-
-			message: "#^Used constant LEVELDB_ZLIB_RAW_COMPRESSION not found\\.$#"
-			path: src/pocketmine/level/format/io/leveldb/LevelDB.php
-			comment: "explicitly checked"
-		-
-			message: "#^Constant LEVELDB_ZLIB_RAW_COMPRESSION not found\\.$#"
-			path: src/pocketmine/level/format/io/leveldb/LevelDB.php
-			comment: "explicitly checked"
-		-
-			message: "#^Instantiated class LevelDB not found\\.$#"
-			path: src/pocketmine/level/format/io/leveldb/LevelDB.php
-			comment: "leveldb extension currently optional"
-		-
-			message: "#^Return typehint of method pocketmine\\\\level\\\\format\\\\io\\\\leveldb\\\\LevelDB\\:\\:createDB\\(\\) has invalid type LevelDB\\.$#"
-			path: src/pocketmine/level/format/io/leveldb/LevelDB.php
-		-
-			message: "#^Return typehint of method pocketmine\\\\level\\\\format\\\\io\\\\leveldb\\\\LevelDB\\:\\:getDatabase\\(\\) has invalid type LevelDB\\.$#"
-			path: src/pocketmine/level/format/io/leveldb/LevelDB.php
+			message: "#^Call to an undefined method pocketmine\\\\command\\\\CommandSender\\:\\:teleport\\(\\)\\.$#"
+			count: 1
+			path: src/pocketmine/command/defaults/TeleportCommand.php
+			comment: "not actually possible, but high cost to fix warning"
diff --git a/src/pocketmine/Server.php b/src/pocketmine/Server.php
index 7342808c7..1cf723eff 100644
--- a/src/pocketmine/Server.php
+++ b/src/pocketmine/Server.php
@@ -228,7 +228,7 @@ class Server{
 	 * @var int
 	 */
 	private $tickCounter = 0;
-	/** @var int */
+	/** @var float */
 	private $nextTick = 0;
 	/** @var float[] */
 	private $tickAverage = [20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20];
@@ -1445,7 +1445,7 @@ class Server{
 	}
 
 	/**
-	 * @return string[]
+	 * @return string[][]
 	 */
 	public function getCommandAliases() : array{
 		$section = $this->getProperty("aliases");
@@ -1790,7 +1790,7 @@ class Server{
 
 	/**
 	 * @param TextContainer|string $message
-	 * @param Player[]             $recipients
+	 * @param CommandSender[]      $recipients
 	 *
 	 * @return int
 	 */
@@ -1799,7 +1799,7 @@ class Server{
 			return $this->broadcast($message, self::BROADCAST_CHANNEL_USERS);
 		}
 
-		/** @var Player[] $recipients */
+		/** @var CommandSender[] $recipients */
 		foreach($recipients as $recipient){
 			$recipient->sendMessage($message);
 		}
diff --git a/src/pocketmine/block/Block.php b/src/pocketmine/block/Block.php
index 0ed6eb803..3fee8b260 100644
--- a/src/pocketmine/block/Block.php
+++ b/src/pocketmine/block/Block.php
@@ -763,7 +763,7 @@ class Block extends Position implements BlockIds, Metadatable{
 			return $this->level->getBlockMetadata()->getMetadata($this, $metadataKey);
 		}
 
-		return null;
+		return [];
 	}
 
 	public function hasMetadata(string $metadataKey) : bool{
diff --git a/src/pocketmine/block/BurningFurnace.php b/src/pocketmine/block/BurningFurnace.php
index 01bbd6779..c189f5b65 100644
--- a/src/pocketmine/block/BurningFurnace.php
+++ b/src/pocketmine/block/BurningFurnace.php
@@ -80,6 +80,9 @@ class BurningFurnace extends Solid{
 			$furnace = $this->getLevel()->getTile($this);
 			if(!($furnace instanceof TileFurnace)){
 				$furnace = Tile::createTile(Tile::FURNACE, $this->getLevel(), TileFurnace::createNBT($this));
+				if(!($furnace instanceof TileFurnace)){
+					return true;
+				}
 			}
 
 			if(!$furnace->canOpenWith($item->getCustomName())){
diff --git a/src/pocketmine/block/Chest.php b/src/pocketmine/block/Chest.php
index b11809ef2..a9cadbb1b 100644
--- a/src/pocketmine/block/Chest.php
+++ b/src/pocketmine/block/Chest.php
@@ -109,6 +109,9 @@ class Chest extends Transparent{
 				$chest = $t;
 			}else{
 				$chest = Tile::createTile(Tile::CHEST, $this->getLevel(), TileChest::createNBT($this));
+				if(!($chest instanceof TileChest)){
+					return true;
+				}
 			}
 
 			if(
diff --git a/src/pocketmine/block/ItemFrame.php b/src/pocketmine/block/ItemFrame.php
index 6038e0a55..6644c682b 100644
--- a/src/pocketmine/block/ItemFrame.php
+++ b/src/pocketmine/block/ItemFrame.php
@@ -47,6 +47,9 @@ class ItemFrame extends Flowable{
 		$tile = $this->level->getTile($this);
 		if(!($tile instanceof TileItemFrame)){
 			$tile = Tile::createTile(Tile::ITEM_FRAME, $this->getLevel(), TileItemFrame::createNBT($this));
+			if(!($tile instanceof TileItemFrame)){
+				return true;
+			}
 		}
 
 		if($tile->hasItem()){
diff --git a/src/pocketmine/command/Command.php b/src/pocketmine/command/Command.php
index 2f47e2029..33b8a645b 100644
--- a/src/pocketmine/command/Command.php
+++ b/src/pocketmine/command/Command.php
@@ -55,7 +55,7 @@ abstract class Command{
 	 */
 	private $activeAliases = [];
 
-	/** @var CommandMap */
+	/** @var CommandMap|null */
 	private $commandMap = null;
 
 	/** @var string */
diff --git a/src/pocketmine/command/defaults/GamemodeCommand.php b/src/pocketmine/command/defaults/GamemodeCommand.php
index 063993aee..6070d7866 100644
--- a/src/pocketmine/command/defaults/GamemodeCommand.php
+++ b/src/pocketmine/command/defaults/GamemodeCommand.php
@@ -60,7 +60,6 @@ class GamemodeCommand extends VanillaCommand{
 			return true;
 		}
 
-		$target = $sender;
 		if(isset($args[1])){
 			$target = $sender->getServer()->getPlayer($args[1]);
 			if($target === null){
@@ -68,7 +67,9 @@ class GamemodeCommand extends VanillaCommand{
 
 				return true;
 			}
-		}elseif(!($sender instanceof Player)){
+		}elseif($sender instanceof Player){
+			$target = $sender;
+		}else{
 			throw new InvalidCommandSyntaxException();
 		}
 
diff --git a/src/pocketmine/entity/Entity.php b/src/pocketmine/entity/Entity.php
index fac66b10c..a2b3468e9 100644
--- a/src/pocketmine/entity/Entity.php
+++ b/src/pocketmine/entity/Entity.php
@@ -318,7 +318,7 @@ abstract class Entity extends Location implements Metadatable, EntityIds{
 	public const DATA_PLAYER_FLAG_DEAD = 2; //TODO: CHECK
 
 	public static $entityCount = 1;
-	/** @var Entity[] */
+	/** @var string[] */
 	private static $knownEntities = [];
 	/** @var string[][] */
 	private static $saveNames = [];
@@ -460,8 +460,8 @@ abstract class Entity extends Location implements Metadatable, EntityIds{
 	/** @var EntityDamageEvent|null */
 	protected $lastDamageCause = null;
 
-	/** @var Block[] */
-	protected $blocksAround = [];
+	/** @var Block[]|null */
+	protected $blocksAround = null;
 
 	/** @var float|null */
 	public $lastX = null;
@@ -2048,7 +2048,7 @@ abstract class Entity extends Location implements Metadatable, EntityIds{
 	 * @param Player $player
 	 */
 	public function spawnTo(Player $player) : void{
-		if(!isset($this->hasSpawned[$player->getLoaderId()])){
+		if(!isset($this->hasSpawned[$player->getLoaderId()]) and $this->chunk !== null and isset($player->usedChunks[Level::chunkHash($this->chunk->getX(), $this->chunk->getZ())])){
 			$this->hasSpawned[$player->getLoaderId()] = $player;
 
 			$this->sendSpawnPacket($player);
diff --git a/src/pocketmine/entity/Squid.php b/src/pocketmine/entity/Squid.php
index abce81095..950164fc0 100644
--- a/src/pocketmine/entity/Squid.php
+++ b/src/pocketmine/entity/Squid.php
@@ -40,7 +40,7 @@ class Squid extends WaterAnimal{
 	public $width = 0.95;
 	public $height = 0.95;
 
-	/** @var Vector3 */
+	/** @var Vector3|null */
 	public $swimDirection = null;
 	public $swimSpeed = 0.1;
 
diff --git a/src/pocketmine/event/player/PlayerChatEvent.php b/src/pocketmine/event/player/PlayerChatEvent.php
index 4ebddecdd..1b8bbcaff 100644
--- a/src/pocketmine/event/player/PlayerChatEvent.php
+++ b/src/pocketmine/event/player/PlayerChatEvent.php
@@ -23,10 +23,12 @@ declare(strict_types=1);
 
 namespace pocketmine\event\player;
 
+use pocketmine\command\CommandSender;
 use pocketmine\event\Cancellable;
 use pocketmine\permission\PermissionManager;
 use pocketmine\Player;
 use pocketmine\Server;
+use function spl_object_id;
 
 /**
  * Called when a player chats something
@@ -39,15 +41,15 @@ class PlayerChatEvent extends PlayerEvent implements Cancellable{
 	protected $format;
 
 	/**
-	 * @var Player[]
+	 * @var CommandSender[]
 	 */
 	protected $recipients = [];
 
 	/**
-	 * @param Player   $player
-	 * @param string   $message
-	 * @param string   $format
-	 * @param Player[] $recipients
+	 * @param Player          $player
+	 * @param string          $message
+	 * @param string          $format
+	 * @param CommandSender[] $recipients
 	 */
 	public function __construct(Player $player, string $message, string $format = "chat.type.text", array $recipients = null){
 		$this->player = $player;
@@ -56,7 +58,11 @@ class PlayerChatEvent extends PlayerEvent implements Cancellable{
 		$this->format = $format;
 
 		if($recipients === null){
-			$this->recipients = PermissionManager::getInstance()->getPermissionSubscriptions(Server::BROADCAST_CHANNEL_USERS);
+			foreach(PermissionManager::getInstance()->getPermissionSubscriptions(Server::BROADCAST_CHANNEL_USERS) as $permissible){
+				if($permissible instanceof CommandSender){
+					$this->recipients[spl_object_id($permissible)] = $permissible;
+				}
+			}
 		}else{
 			$this->recipients = $recipients;
 		}
@@ -100,14 +106,14 @@ class PlayerChatEvent extends PlayerEvent implements Cancellable{
 	}
 
 	/**
-	 * @return Player[]
+	 * @return CommandSender[]
 	 */
 	public function getRecipients() : array{
 		return $this->recipients;
 	}
 
 	/**
-	 * @param Player[] $recipients
+	 * @param CommandSender[] $recipients
 	 */
 	public function setRecipients(array $recipients) : void{
 		$this->recipients = $recipients;
diff --git a/src/pocketmine/event/player/PlayerCreationEvent.php b/src/pocketmine/event/player/PlayerCreationEvent.php
index a67be8792..f79a3411d 100644
--- a/src/pocketmine/event/player/PlayerCreationEvent.php
+++ b/src/pocketmine/event/player/PlayerCreationEvent.php
@@ -39,15 +39,15 @@ class PlayerCreationEvent extends Event{
 	/** @var int */
 	private $port;
 
-	/** @var Player::class */
+	/** @var string */
 	private $baseClass;
-	/** @var Player::class */
+	/** @var string */
 	private $playerClass;
 
 	/**
 	 * @param SourceInterface $interface
-	 * @param Player::class   $baseClass
-	 * @param Player::class   $playerClass
+	 * @param string          $baseClass
+	 * @param string          $playerClass
 	 * @param string          $address
 	 * @param int             $port
 	 */
@@ -91,14 +91,14 @@ class PlayerCreationEvent extends Event{
 	}
 
 	/**
-	 * @return Player::class
+	 * @return string
 	 */
 	public function getBaseClass(){
 		return $this->baseClass;
 	}
 
 	/**
-	 * @param Player::class $class
+	 * @param string $class
 	 */
 	public function setBaseClass($class){
 		if(!is_a($class, $this->baseClass, true)){
@@ -109,14 +109,14 @@ class PlayerCreationEvent extends Event{
 	}
 
 	/**
-	 * @return Player::class
+	 * @return string
 	 */
 	public function getPlayerClass(){
 		return $this->playerClass;
 	}
 
 	/**
-	 * @param Player::class $class
+	 * @param string $class
 	 */
 	public function setPlayerClass($class){
 		if(!is_a($class, $this->baseClass, true)){
diff --git a/src/pocketmine/inventory/BaseInventory.php b/src/pocketmine/inventory/BaseInventory.php
index bc6f7dcfb..b703442d6 100644
--- a/src/pocketmine/inventory/BaseInventory.php
+++ b/src/pocketmine/inventory/BaseInventory.php
@@ -47,7 +47,7 @@ abstract class BaseInventory implements Inventory{
 	/** @var string */
 	protected $title;
 	/** @var \SplFixedArray|Item[] */
-	protected $slots = [];
+	protected $slots;
 	/** @var Player[] */
 	protected $viewers = [];
 	/** @var InventoryEventProcessor */
diff --git a/src/pocketmine/inventory/CraftingManager.php b/src/pocketmine/inventory/CraftingManager.php
index 33dba506f..bec35765a 100644
--- a/src/pocketmine/inventory/CraftingManager.php
+++ b/src/pocketmine/inventory/CraftingManager.php
@@ -43,7 +43,7 @@ class CraftingManager{
 	/** @var FurnaceRecipe[] */
 	protected $furnaceRecipes = [];
 
-	/** @var BatchPacket */
+	/** @var BatchPacket|null */
 	private $craftingDataCache;
 
 	public function __construct(){
diff --git a/src/pocketmine/item/enchantment/Enchantment.php b/src/pocketmine/item/enchantment/Enchantment.php
index 80831911e..58dfba841 100644
--- a/src/pocketmine/item/enchantment/Enchantment.php
+++ b/src/pocketmine/item/enchantment/Enchantment.php
@@ -94,7 +94,7 @@ class Enchantment{
 	public const SLOT_ELYTRA = 0x4000;
 	public const SLOT_TRIDENT = 0x8000;
 
-	/** @var Enchantment[] */
+	/** @var \SplFixedArray|Enchantment[] */
 	protected static $enchantments;
 
 	public static function init() : void{
diff --git a/src/pocketmine/level/Level.php b/src/pocketmine/level/Level.php
index 6fc37039a..2dbf4073d 100644
--- a/src/pocketmine/level/Level.php
+++ b/src/pocketmine/level/Level.php
@@ -265,7 +265,7 @@ class Level implements ChunkManager, Metadatable{
 	/** @var LevelTimings */
 	public $timings;
 
-	/** @var int */
+	/** @var float */
 	public $tickRateTime = 0;
 	/**
 	 * @deprecated
diff --git a/src/pocketmine/level/format/Chunk.php b/src/pocketmine/level/format/Chunk.php
index 8bbdefe19..5847dd0ab 100644
--- a/src/pocketmine/level/format/Chunk.php
+++ b/src/pocketmine/level/format/Chunk.php
@@ -694,50 +694,48 @@ class Chunk{
 	public function initChunk(Level $level){
 		if(!$this->isInit){
 			$changed = false;
-			if($this->NBTentities !== null){
-				$level->timings->syncChunkLoadEntitiesTimer->startTiming();
-				foreach($this->NBTentities as $nbt){
-					if($nbt instanceof CompoundTag){
-						if(!$nbt->hasTag("id")){ //allow mixed types (because of leveldb)
-							$changed = true;
-							continue;
-						}
 
-						try{
-							$entity = Entity::createEntity($nbt->getTag("id")->getValue(), $level, $nbt);
-							if(!($entity instanceof Entity)){
-								$changed = true;
-								continue;
-							}
-						}catch(\Throwable $t){
-							$level->getServer()->getLogger()->logException($t);
+			$level->timings->syncChunkLoadEntitiesTimer->startTiming();
+			foreach($this->NBTentities as $nbt){
+				if($nbt instanceof CompoundTag){
+					if(!$nbt->hasTag("id")){ //allow mixed types (because of leveldb)
+						$changed = true;
+						continue;
+					}
+
+					try{
+						$entity = Entity::createEntity($nbt->getTag("id")->getValue(), $level, $nbt);
+						if(!($entity instanceof Entity)){
 							$changed = true;
 							continue;
 						}
+					}catch(\Throwable $t){
+						$level->getServer()->getLogger()->logException($t);
+						$changed = true;
+						continue;
 					}
 				}
-				$level->timings->syncChunkLoadEntitiesTimer->stopTiming();
-
-				$level->timings->syncChunkLoadTileEntitiesTimer->startTiming();
-				foreach($this->NBTtiles as $nbt){
-					if($nbt instanceof CompoundTag){
-						if(!$nbt->hasTag(Tile::TAG_ID, StringTag::class)){
-							$changed = true;
-							continue;
-						}
-
-						if(Tile::createTile($nbt->getString(Tile::TAG_ID), $level, $nbt) === null){
-							$changed = true;
-							continue;
-						}
-					}
-				}
-
-				$level->timings->syncChunkLoadTileEntitiesTimer->stopTiming();
-
-				$this->NBTentities = null;
-				$this->NBTtiles = null;
 			}
+			$this->NBTentities = [];
+			$level->timings->syncChunkLoadEntitiesTimer->stopTiming();
+
+			$level->timings->syncChunkLoadTileEntitiesTimer->startTiming();
+			foreach($this->NBTtiles as $nbt){
+				if($nbt instanceof CompoundTag){
+					if(!$nbt->hasTag(Tile::TAG_ID, StringTag::class)){
+						$changed = true;
+						continue;
+					}
+
+					if(Tile::createTile($nbt->getString(Tile::TAG_ID), $level, $nbt) === null){
+						$changed = true;
+						continue;
+					}
+				}
+			}
+
+			$this->NBTtiles = [];
+			$level->timings->syncChunkLoadTileEntitiesTimer->stopTiming();
 
 			$this->hasChanged = $changed;
 
diff --git a/src/pocketmine/network/mcpe/NetworkBinaryStream.php b/src/pocketmine/network/mcpe/NetworkBinaryStream.php
index 32a3629e9..85c6766ab 100644
--- a/src/pocketmine/network/mcpe/NetworkBinaryStream.php
+++ b/src/pocketmine/network/mcpe/NetworkBinaryStream.php
@@ -93,7 +93,11 @@ class NetworkBinaryStream extends BinaryStream{
 			if($c !== 1){
 				throw new \UnexpectedValueException("Unexpected NBT count $c");
 			}
-			$nbt = (new NetworkLittleEndianNBTStream())->read($this->buffer, false, $this->offset, 512);
+			$decodedNBT = (new NetworkLittleEndianNBTStream())->read($this->buffer, false, $this->offset, 512);
+			if(!($decodedNBT instanceof CompoundTag)){
+				throw new \UnexpectedValueException("Unexpected root tag type for itemstack");
+			}
+			$nbt = $decodedNBT;
 		}elseif($nbtLen !== 0){
 			throw new \UnexpectedValueException("Unexpected fake NBT length $nbtLen");
 		}
diff --git a/src/pocketmine/network/mcpe/protocol/AvailableCommandsPacket.php b/src/pocketmine/network/mcpe/protocol/AvailableCommandsPacket.php
index 9af852bba..86088c8dc 100644
--- a/src/pocketmine/network/mcpe/protocol/AvailableCommandsPacket.php
+++ b/src/pocketmine/network/mcpe/protocol/AvailableCommandsPacket.php
@@ -227,6 +227,7 @@ class AvailableCommandsPacket extends DataPacket{
 		$retval->aliases = $enums[$this->getLInt()] ?? null;
 
 		for($overloadIndex = 0, $overloadCount = $this->getUnsignedVarInt(); $overloadIndex < $overloadCount; ++$overloadIndex){
+			$retval->overloads[$overloadIndex] = [];
 			for($paramIndex = 0, $paramCount = $this->getUnsignedVarInt(); $paramIndex < $paramCount; ++$paramIndex){
 				$parameter = new CommandParameter();
 				$parameter->paramName = $this->getString();
diff --git a/src/pocketmine/network/mcpe/protocol/CraftingDataPacket.php b/src/pocketmine/network/mcpe/protocol/CraftingDataPacket.php
index 27f59e73b..bb5f7cd8f 100644
--- a/src/pocketmine/network/mcpe/protocol/CraftingDataPacket.php
+++ b/src/pocketmine/network/mcpe/protocol/CraftingDataPacket.php
@@ -140,7 +140,7 @@ class CraftingDataPacket extends DataPacket{
 			}
 			$this->decodedEntries[] = $entry;
 		}
-		$this->getBool(); //cleanRecipes
+		$this->cleanRecipes = $this->getBool();
 	}
 
 	private static function writeEntry($entry, NetworkBinaryStream $stream, int $pos){
diff --git a/src/pocketmine/network/mcpe/protocol/DataPacket.php b/src/pocketmine/network/mcpe/protocol/DataPacket.php
index f2e60caa5..aeeeaf054 100644
--- a/src/pocketmine/network/mcpe/protocol/DataPacket.php
+++ b/src/pocketmine/network/mcpe/protocol/DataPacket.php
@@ -135,7 +135,7 @@ abstract class DataPacket extends NetworkBinaryStream{
 	abstract public function handle(NetworkSession $session) : bool;
 
 	public function clean(){
-		$this->buffer = null;
+		$this->buffer = "";
 		$this->isEncoded = false;
 		$this->offset = 0;
 		return $this;
diff --git a/src/pocketmine/scheduler/AsyncPool.php b/src/pocketmine/scheduler/AsyncPool.php
index a0b6200b0..069da62de 100644
--- a/src/pocketmine/scheduler/AsyncPool.php
+++ b/src/pocketmine/scheduler/AsyncPool.php
@@ -262,6 +262,7 @@ class AsyncPool{
 			while(($task = $worker->unstack()) !== null){
 				//cancelRun() is not strictly necessary here, but it might be used to inform plugins of the task state
 				//(i.e. it never executed).
+				assert($task instanceof AsyncTask);
 				$task->cancelRun();
 				$this->removeTask($task, true);
 			}
diff --git a/tests/phpstan/configs/optional-com-dotnet.neon b/tests/phpstan/configs/optional-com-dotnet.neon
new file mode 100644
index 000000000..efa2d82ab
--- /dev/null
+++ b/tests/phpstan/configs/optional-com-dotnet.neon
@@ -0,0 +1,12 @@
+parameters:
+	ignoreErrors:
+		-
+			message: "#^Instantiated class COM not found\\.$#"
+			count: 2
+			path: src/pocketmine/network/upnp/UPnP.php
+
+		-
+			message: "#^Access to property \\$StaticPortMappingCollection on an unknown class COM\\.$#"
+			count: 4
+			path: src/pocketmine/network/upnp/UPnP.php
+
diff --git a/tests/phpstan/configs/optional-leveldb.neon b/tests/phpstan/configs/optional-leveldb.neon
new file mode 100644
index 000000000..7ad8f1e28
--- /dev/null
+++ b/tests/phpstan/configs/optional-leveldb.neon
@@ -0,0 +1,30 @@
+parameters:
+	ignoreErrors:
+		-
+			message: "#^Used constant LEVELDB_ZLIB_RAW_COMPRESSION not found\\.$#"
+			path: src/pocketmine/level/format/io/leveldb/LevelDB.php
+
+		-
+			message: "#^Constant LEVELDB_ZLIB_RAW_COMPRESSION not found\\.$#"
+			path: src/pocketmine/level/format/io/leveldb/LevelDB.php
+
+		-
+			message: "#^Instantiated class LevelDB not found\\.$#"
+			path: src/pocketmine/level/format/io/leveldb/LevelDB.php
+
+		-
+			message: "#^Return typehint of method pocketmine\\\\level\\\\format\\\\io\\\\leveldb\\\\LevelDB\\:\\:createDB\\(\\) has invalid type LevelDB\\.$#"
+			path: src/pocketmine/level/format/io/leveldb/LevelDB.php
+
+		-
+			message: "#^Return typehint of method pocketmine\\\\level\\\\format\\\\io\\\\leveldb\\\\LevelDB\\:\\:getDatabase\\(\\) has invalid type LevelDB\\.$#"
+			path: src/pocketmine/level/format/io/leveldb/LevelDB.php
+
+		-
+			message: "#^Property pocketmine\\\\level\\\\format\\\\io\\\\leveldb\\\\LevelDB\\:\\:\\$db has unknown class LevelDB as its type\\.$#"
+			path: src/pocketmine/level/format/io/leveldb/LevelDB.php
+
+		-
+			message: "#^Call to method (get|put|delete|close)\\(\\) on an unknown class LevelDB\\.$#"
+			path: src/pocketmine/level/format/io/leveldb/LevelDB.php
+
diff --git a/tests/phpstan/configs/phpstan-bugs.neon b/tests/phpstan/configs/phpstan-bugs.neon
new file mode 100644
index 000000000..90fef5cea
--- /dev/null
+++ b/tests/phpstan/configs/phpstan-bugs.neon
@@ -0,0 +1,10 @@
+parameters:
+	ignoreErrors:
+		-
+			message: "#^PHPDoc tag @param has invalid value \\(.+\\)\\: Unexpected token \"&\", expected TOKEN_VARIABLE at offset \\d+$#"
+			path: src/pocketmine
+
+		-
+			message: "#^Default value of the parameter \\#\\d+ \\$[A-Za-z\\d_]+ \\(\\-?\\d+\\) of method .+\\(\\) is incompatible with type float\\.$#"
+			path: src/pocketmine
+
diff --git a/tests/phpstan/configs/pthreads-bugs.neon b/tests/phpstan/configs/pthreads-bugs.neon
new file mode 100644
index 000000000..65979a989
--- /dev/null
+++ b/tests/phpstan/configs/pthreads-bugs.neon
@@ -0,0 +1,6 @@
+parameters:
+	ignoreErrors:
+		-
+			message: "#^Variable \\$GLOBALS in isset\\(\\) always exists and is not nullable\\.$#"
+			path: src/pocketmine/MemoryManager.php
+