diff --git a/src/pocketmine/Player.php b/src/pocketmine/Player.php
index 8b0944f33..2d0a5b3de 100644
--- a/src/pocketmine/Player.php
+++ b/src/pocketmine/Player.php
@@ -2210,15 +2210,16 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 		/** @var InventoryAction[] $actions */
 		$actions = [];
 		foreach($packet->actions as $networkInventoryAction){
-			$action = $networkInventoryAction->createInventoryAction($this);
-
-			if($action === null){
-				$this->server->getLogger()->debug("Unmatched inventory action from " . $this->getName() . ": " . json_encode($networkInventoryAction));
+			try{
+				$action = $networkInventoryAction->createInventoryAction($this);
+				if($action !== null){
+					$actions[] = $action;
+				}
+			}catch(\Throwable $e){
+				$this->server->getLogger()->debug("Unhandled inventory action from " . $this->getName() . ": " . $e->getMessage());
 				$this->sendAllInventories();
 				return false;
 			}
-
-			$actions[] = $action;
 		}
 
 		if($packet->isCraftingPart){
diff --git a/src/pocketmine/network/mcpe/protocol/types/NetworkInventoryAction.php b/src/pocketmine/network/mcpe/protocol/types/NetworkInventoryAction.php
index 18663b037..27ed44d02 100644
--- a/src/pocketmine/network/mcpe/protocol/types/NetworkInventoryAction.php
+++ b/src/pocketmine/network/mcpe/protocol/types/NetworkInventoryAction.php
@@ -170,13 +170,13 @@ class NetworkInventoryAction{
 					return new SlotChangeAction($window, $this->inventorySlot, $this->oldItem, $this->newItem);
 				}
 
-				return null;
+				throw new \InvalidStateException("Player " . $player->getName() . " has no open container with window ID $this->windowId");
 			case self::SOURCE_WORLD:
-				if($this->inventorySlot === self::ACTION_MAGIC_SLOT_DROP_ITEM){
-					return new DropItemAction($this->oldItem, $this->newItem);
+				if($this->inventorySlot !== self::ACTION_MAGIC_SLOT_DROP_ITEM){
+					throw new \UnexpectedValueException("Only expecting drop-item world actions from the client!");
 				}
 
-				return null;
+				return new DropItemAction($this->oldItem, $this->newItem);
 			case self::SOURCE_CREATIVE:
 				switch($this->inventorySlot){
 					case self::ACTION_MAGIC_SLOT_CREATIVE_DELETE_ITEM:
@@ -186,7 +186,7 @@ class NetworkInventoryAction{
 						$type = CreativeInventoryAction::TYPE_CREATE_ITEM;
 						break;
 					default:
-						return null;
+						throw new \UnexpectedValueException("Unexpected creative action type $this->inventorySlot");
 
 				}
 
@@ -210,16 +210,16 @@ class NetworkInventoryAction{
 						//DROP_CONTENTS doesn't bother telling us what slot the item is in, so we find it ourselves
 						$inventorySlot = $window->first($this->oldItem, true);
 						if($inventorySlot === -1){
-							return null;
+							throw new \InvalidStateException("Fake container " . get_class($window) . " for " . $player->getName() . " does not contain $this->oldItem");
 						}
 						return new SlotChangeAction($window, $inventorySlot, $this->oldItem, $this->newItem);
 				}
 
 				//TODO: more stuff
-				return null;
+				throw new \UnexpectedValueException("Player " . $player->getName() . " has no open container with window ID $this->windowId");
+			default:
+				throw new \UnexpectedValueException("Unknown inventory source type $this->sourceType");
 		}
-
-		return null;
 	}
 
 }
\ No newline at end of file