You can't create private store - sell without contents.

L2_GameServer/java/net/sf/l2j/gameserver/network/SystemMessageId.java

@@ -2056,7 +2056,17 @@ public enum SystemMessageId
 	*/
 	CHAT_DISABLED(346),
 
-	// 347 - 348: empty
+	/**
+	* ID: 347<br>
+	* Message: Incorrect item count.
+	*/
+	INCORRECT_ITEM_COUNT(347),
+
+	/**
+	* ID: 348<br>
+	* Message: Incorrect item price.
+	*/
+	INCORRECT_ITEM_PRICE(348),
 
 	/**
 	* ID: 349<br>

L2_GameServer/java/net/sf/l2j/gameserver/network/clientpackets/SetPrivateStoreListSell.java

@@ -47,7 +47,7 @@ public class SetPrivateStoreListSell extends L2GameClientPacket
 	{
 		_packageSale = (readD() == 1);
 		int count = readD();
-		if (count < 0
+		if (count < 1
 				|| count > Config.MAX_ITEM_IN_PACKET
 				|| count * BATCH_LENGTH != _buf.remaining())
 		{
@@ -79,6 +79,7 @@ public class SetPrivateStoreListSell extends L2GameClientPacket
 
 		if (_items == null)
 		{
+			player.sendPacket(new SystemMessage(SystemMessageId.INCORRECT_ITEM_COUNT));
 			player.setPrivateStoreType(L2PcInstance.STORE_PRIVATE_NONE);
 			player.broadcastUserInfo();
 			return;