diff --git a/src/pocketmine/Player.php b/src/pocketmine/Player.php
index 368fa25b1..c65a7f26f 100644
--- a/src/pocketmine/Player.php
+++ b/src/pocketmine/Player.php
@@ -623,7 +623,7 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 	public function sendCommandData(){
 		$pk = new AvailableCommandsPacket();
 		foreach($this->server->getCommandMap()->getCommands() as $name => $command){
-			if(isset($pk->commandData[$command->getName()]) or $command->getName() === "help"){
+			if(isset($pk->commandData[$command->getName()]) or $command->getName() === "help" or !$command->testPermissionSilent($this)){
 				continue;
 			}
 
diff --git a/src/pocketmine/event/Event.php b/src/pocketmine/event/Event.php
index a1a3f176b..34d53c72e 100644
--- a/src/pocketmine/event/Event.php
+++ b/src/pocketmine/event/Event.php
@@ -50,7 +50,7 @@ abstract class Event{
 	 */
 	public function isCancelled() : bool{
 		if(!($this instanceof Cancellable)){
-			throw new \BadMethodCallException("Event is not Cancellable");
+			throw new \BadMethodCallException(get_class($this) . " is not Cancellable");
 		}
 
 		/** @var Event $this */
@@ -64,7 +64,7 @@ abstract class Event{
 	 */
 	public function setCancelled(bool $value = true) : void{
 		if(!($this instanceof Cancellable)){
-			throw new \BadMethodCallException("Event is not Cancellable");
+			throw new \BadMethodCallException(get_class($this) . " is not Cancellable");
 		}
 
 		/** @var Event $this */
diff --git a/src/pocketmine/network/mcpe/handler/SimpleSessionHandler.php b/src/pocketmine/network/mcpe/handler/SimpleSessionHandler.php
index 885d47536..35b463645 100644
--- a/src/pocketmine/network/mcpe/handler/SimpleSessionHandler.php
+++ b/src/pocketmine/network/mcpe/handler/SimpleSessionHandler.php
@@ -77,6 +77,11 @@ class SimpleSessionHandler extends SessionHandler{
 	/** @var CraftingTransaction|null */
 	protected $craftingTransaction = null;
 
+	/** @var float */
+	protected $lastRightClickTime = 0.0;
+	/** @var Vector3|null */
+	protected $lastRightClickPos = null;
+
 	public function __construct(Player $player){
 		$this->player = $player;
 	}
@@ -184,6 +189,18 @@ class SimpleSessionHandler extends SessionHandler{
 				$type = $packet->trData->actionType;
 				switch($type){
 					case InventoryTransactionPacket::USE_ITEM_ACTION_CLICK_BLOCK:
+						//TODO: start hack for client spam bug
+						$spamBug = ($this->lastRightClickPos !== null and
+							microtime(true) - $this->lastRightClickTime < 0.1 and //100ms
+							$this->lastRightClickPos->distanceSquared($packet->trData->clickPos) < 0.00001 //signature spam bug has 0 distance, but allow some error
+						);
+						//get rid of continued spam if the player clicks and holds right-click
+						$this->lastRightClickPos = clone $packet->trData->clickPos;
+						$this->lastRightClickTime = microtime(true);
+						if($spamBug){
+							return true;
+						}
+						//TODO: end hack for client spam bug
 						$this->player->interactBlock($blockVector, $face, $packet->trData->clickPos);
 						return true;
 					case InventoryTransactionPacket::USE_ITEM_ACTION_BREAK_BLOCK: