diff --git a/src/pocketmine/event/Event.php b/src/pocketmine/event/Event.php
index a5575f47a..78744412d 100644
--- a/src/pocketmine/event/Event.php
+++ b/src/pocketmine/event/Event.php
@@ -46,8 +46,13 @@ abstract class Event{
 
 	/**
 	 * @return bool
+	 *
+	 * @throws \BadMethodCallException
 	 */
 	public function isCancelled(){
+		if(!($this instanceof Cancellable)){
+			throw new \BadMethodCallException("Event is not Cancellable");
+		}
 		return $this->isCancelled === true;
 	}
 
@@ -55,8 +60,13 @@ abstract class Event{
 	 * @param bool $value
 	 *
 	 * @return bool
+	 *
+	 * @throws \BadMethodCallException
 	 */
 	public function setCancelled($value = true){
+		if(!($this instanceof Cancellable)){
+			throw new \BadMethodCallException("Event is not Cancellable");
+		}
 		$this->isCancelled = (bool) $value;
 	}
 
diff --git a/src/pocketmine/tile/Sign.php b/src/pocketmine/tile/Sign.php
index 23086e24c..d893551c7 100644
--- a/src/pocketmine/tile/Sign.php
+++ b/src/pocketmine/tile/Sign.php
@@ -33,14 +33,26 @@ class Sign extends Spawnable{
 
 	public function __construct(Chunk $chunk, Compound $nbt){
 		$nbt["id"] = Tile::SIGN;
+		if(!isset($nbt->Text1)){
+			$nbt->Text1 = new String("Text1", "");
+		}
+		if(!isset($nbt->Text2)){
+			$nbt->Text2 = new String("Text2", "");
+		}
+		if(!isset($nbt->Text3)){
+			$nbt->Text3 = new String("Text3", "");
+		}
+		if(!isset($nbt->Text4)){
+			$nbt->Text4 = new String("Text4", "");
+		}
 		parent::__construct($chunk, $nbt);
 	}
 
 	public function setText($line1 = "", $line2 = "", $line3 = "", $line4 = ""){
-		$this->namedtag->Text1 = $line1;
-		$this->namedtag->Text2 = $line2;
-		$this->namedtag->Text3 = $line3;
-		$this->namedtag->Text4 = $line4;
+		$this->namedtag->Text1 = new String("Text1", $line1);
+		$this->namedtag->Text2 = new String("Text2", $line2);
+		$this->namedtag->Text3 = new String("Text3", $line3);
+		$this->namedtag->Text4 = new String("Text4", $line4);
 		$this->spawnToAll();
 
 		return true;
@@ -48,10 +60,10 @@ class Sign extends Spawnable{
 
 	public function getText(){
 		return array(
-			$this->namedtag->Text1,
-			$this->namedtag->Text2,
-			$this->namedtag->Text3,
-			$this->namedtag->Text4
+			$this->namedtag["Text1"],
+			$this->namedtag["Text2"],
+			$this->namedtag["Text3"],
+			$this->namedtag["Text4"]
 		);
 	}
 
@@ -62,10 +74,10 @@ class Sign extends Spawnable{
 
 		$nbt = new NBT(NBT::LITTLE_ENDIAN);
 		$nbt->setData(new Compound("", array(
-			new String("Text1", $this->namedtag->Text1),
-			new String("Text2", $this->namedtag->Text2),
-			new String("Text3", $this->namedtag->Text3),
-			new String("Text4", $this->namedtag->Text4),
+			new String("Text1", $this->namedtag["Text1"]),
+			new String("Text2", $this->namedtag["Text2"]),
+			new String("Text3", $this->namedtag["Text4"]),
+			new String("Text4", $this->namedtag["Text4"]),
 			new String("id", Tile::SIGN),
 			new Int("x", (int) $this->x),
 			new Int("y", (int) $this->y),