
You cannot change the inventory item category; item has been used in one or more transactions
In the Item Master Data window, you have created an item without selecting the Inventory Item checkbox.
You have created one or more transactions with the item selected.
Note
Transactions refer to postings to accounts or documents.
You have attempted to reselect the Inventory Item checkbox.
SAP does not allow you to change the inventory item category if the item is used in one or more transactions.