diff --git a/src/pocketmine/Player.php b/src/pocketmine/Player.php
index de955ce73e..b7ebf1c914 100644
--- a/src/pocketmine/Player.php
+++ b/src/pocketmine/Player.php
@@ -351,7 +351,7 @@ class Player extends Human implements CommandSender, InventoryHolder, ChunkLoade
 	 * @return bool
 	 */
 	public function canSee(Player $player){
-		return !isset($this->hiddenPlayers[$player->getName()]);
+		return !isset($this->hiddenPlayers[$player->getUniqueId()]);
 	}
 
 	/**
@@ -361,7 +361,7 @@ class Player extends Human implements CommandSender, InventoryHolder, ChunkLoade
 		if($player === $this){
 			return;
 		}
-		$this->hiddenPlayers[$player->getName()] = $player;
+		$this->hiddenPlayers[$player->getUniqueId()] = $player;
 		$player->despawnFrom($this);
 	}
 
@@ -372,7 +372,7 @@ class Player extends Human implements CommandSender, InventoryHolder, ChunkLoade
 		if($player === $this){
 			return;
 		}
-		unset($this->hiddenPlayers[$player->getName()]);
+		unset($this->hiddenPlayers[$player->getUniqueId()]);
 		if($player->isOnline()){
 			$player->spawnTo($this);
 		}
@@ -2735,14 +2735,14 @@ class Player extends Human implements CommandSender, InventoryHolder, ChunkLoade
 	public function close($message = "", $reason = "generic reason", $notify = true){
 
 		if($this->connected and !$this->closed){
-			if($notify and $reason != ""){
+			if($notify and strlen((string) $reason) > 0){
 				$pk = new DisconnectPacket;
 				$pk->message = $reason;
 				$this->directDataPacket($pk->setChannel(Network::CHANNEL_PRIORITY));
 			}
 			
 			$this->connected = false;
-			if($this->username != ""){
+			if(strlen($this->getName()) > 0){
 				$this->server->getPluginManager()->callEvent($ev = new PlayerQuitEvent($this, $message));
 				if($this->server->getAutoSave() and $this->loggedIn === true){
 					$this->save();
diff --git a/src/pocketmine/Server.php b/src/pocketmine/Server.php
index a0546d71a7..5a218e2200 100644
--- a/src/pocketmine/Server.php
+++ b/src/pocketmine/Server.php
@@ -91,6 +91,7 @@ use pocketmine\plugin\PharPluginLoader;
 use pocketmine\plugin\Plugin;
 use pocketmine\plugin\PluginLoadOrder;
 use pocketmine\plugin\PluginManager;
+use pocketmine\scheduler\FileWriteTask;
 use pocketmine\scheduler\SendUsageTask;
 use pocketmine\scheduler\ServerScheduler;
 use pocketmine\tile\Chest;
@@ -843,7 +844,8 @@ class Server{
 		$nbt = new NBT(NBT::BIG_ENDIAN);
 		try{
 			$nbt->setData($nbtTag);
-			file_put_contents($this->getDataPath() . "players/" . strtolower($name) . ".dat", $nbt->writeCompressed());
+
+			$this->getScheduler()->scheduleAsyncTask(new FileWriteTask($this->getDataPath() . "players/" . strtolower($name) . ".dat", $nbt->writeCompressed()));
 		}catch(\Exception $e){
 			$this->logger->critical($this->getLanguage()->translateString("pocketmine.data.saveError", [$name, $e->getMessage()]));
 			if(\pocketmine\DEBUG > 1 and $this->logger instanceof MainLogger){
diff --git a/src/pocketmine/scheduler/FileWriteTask.php b/src/pocketmine/scheduler/FileWriteTask.php
new file mode 100644
index 0000000000..f952e91e85
--- /dev/null
+++ b/src/pocketmine/scheduler/FileWriteTask.php
@@ -0,0 +1,43 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+namespace pocketmine\scheduler;
+
+class FileWriteTask extends AsyncTask{
+
+	private $path;
+	private $contents;
+	private $flags;
+
+	public function __construct($path, $contents, $flags = 0){
+		$this->path = $path;
+		$this->contents = $contents;
+		$this->flags = (int) $flags;
+	}
+
+	public function onRun(){
+		try{
+			file_put_contents($this->path, $this->contents, (int) $this->flags);
+		}catch (\Exception $e){
+
+		}
+	}
+}
diff --git a/src/pocketmine/utils/Config.php b/src/pocketmine/utils/Config.php
index 38364e2e93..80b8e69d22 100644
--- a/src/pocketmine/utils/Config.php
+++ b/src/pocketmine/utils/Config.php
@@ -20,6 +20,7 @@
 */
 
 namespace pocketmine\utils;
+use pocketmine\scheduler\FileWriteTask;
 use pocketmine\Server;
 
 
@@ -170,9 +171,11 @@ class Config{
 	}
 
 	/**
+	 * @param bool $async
+	 *
 	 * @return boolean
 	 */
-	public function save(){
+	public function save($async = false){
 		if($this->correct === true){
 			try{
 				$content = null;
@@ -194,7 +197,12 @@ class Config{
 						$content = implode("\r\n", array_keys($this->config));
 						break;
 				}
-				file_put_contents($this->file, $content);
+
+				if($async){
+					Server::getInstance()->getScheduler()->scheduleAsyncTask(new FileWriteTask($this->file, $content));
+				}else{
+					file_put_contents($this->file, $content);
+				}
 			}catch(\Exception $e){
 				$logger = Server::getInstance()->getLogger();
 				$logger->critical("Could not save Config " . $this->file . ": " . $e->getMessage());