If you have asset with rotating item associated to it you can't change its classification, to change its classification you need to remove by select action change item number and classification becomes editable on asset application.
This is a bug steps to reproduce it are 1. Create a invusage record to transfer storeroom to another. 2. change status to shipped. 3. Go to shipment receiving and do partial receiving. 4. return partial recieved items. 5. try to recieve remaining items you will get error.