fix

src/InventoryContentPacket.php

@@ -52,8 +52,8 @@ protected function decodePayload(PacketSerializer $in) : void{
 				$this->containerName = FullContainerName::read($in);
 				$this->dynamicContainerSize = $in->getUnsignedVarInt();
 			}else {
-				$dynamicContainerId = $in->getUnsignedVarInt();
-				$this->containerName = new FullContainerName(0, $dynamicContainerId);
+				$in->getUnsignedVarInt(); // ignore
+				$this->containerName = new FullContainerName(0);
 			}
 		}
 	}
@@ -69,7 +69,7 @@ protected function encodePayload(PacketSerializer $out) : void{
 				$this->containerName->write($out);
 				$out->putUnsignedVarInt($this->dynamicContainerSize);
 			}else{
-				$out->putUnsignedVarInt($this->containerName->getDynamicId());
+				$out->putUnsignedVarInt(0);
 			}
 		}
 	}

src/InventorySlotPacket.php

@@ -48,7 +48,8 @@ protected function decodePayload(PacketSerializer $in) : void{
 				$this->containerName = FullContainerName::read($in);
 				$this->dynamicContainerSize = $in->getUnsignedVarInt();
 			}else{
-				$this->containerName = new FullContainerName(0, $in->getUnsignedVarInt());
+				$in->getUnsignedVarInt(); // ignore
+				$this->containerName = new FullContainerName(0);
 			}
 		}
 		$this->item = ItemStackWrapper::read($in);
@@ -62,7 +63,7 @@ protected function encodePayload(PacketSerializer $out) : void{
 				$this->containerName->write($out);
 				$out->putUnsignedVarInt($this->dynamicContainerSize);
 			}else{
-				$out->putUnsignedVarInt($this->containerName->getDynamicId());
+				$out->putUnsignedVarInt(0);
 			}
 		}
 		$this->item->write($out);

src/types/inventory/FullContainerName.php

@@ -14,6 +14,7 @@
 
 namespace pocketmine\network\mcpe\protocol\types\inventory;
 
+use pocketmine\network\mcpe\protocol\ProtocolInfo;
 use pocketmine\network\mcpe\protocol\serializer\PacketSerializer;
 
 final class FullContainerName{
@@ -28,12 +29,17 @@ public function getDynamicId() : ?int{ return $this->dynamicId; }
 
 	public static function read(PacketSerializer $in) : self{
 		$containerId = $in->getByte();
-		$dynamicId = $in->readOptional($in->getLInt(...));
+		$dynamicId = $in->getProtocol() >= ProtocolInfo::PROTOCOL_729 ?
+			$in->readOptional($in->getLInt(...)) : $in->getLInt();
 		return new self($containerId, $dynamicId);
 	}
 
 	public function write(PacketSerializer $out) : void{
 		$out->putByte($this->containerId);
-		$out->writeOptional($this->dynamicId, $out->putLInt(...));
+		if($out->getProtocol() >= ProtocolInfo::PROTOCOL_729) {
+			$out->writeOptional($this->dynamicId, $out->putLInt(...));
+		}else{
+			$out->putLInt($this->dynamicId);
+		}
 	}
 }