Issue while consuming Inventory Manager business service

Hello,

I am trying to consume the Inventory Manager business service and when I came to call the function show item price, I tried to execute the code below but the last line was producing an error. Can anyone help in this?

	getItemPrice itemPrice = new getItemPrice();

	itemPrice.item = new itemGroupCustomer();
	itemPrice.item.itemId = ItemID;
	itemPrice.branchPlantList = BusinessUnit var showItemPrice = manager.getItemPrice(itemPrice);

Invalid Array length. WhereClause conditions array passed to WhereClauseBuilder is empty. Please use emptyWhereClauseBuilder construct if no where clause is desired. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.