https://userapps.support.sap.com/sap/support/knowledge/en/2666737
2666737 - Error M7104 in MB1B for QI to Unrestricted Transfer Posting - SAP ERP & S/4HANA | SAP...
The error message no. M7104 - 'Stock to be removed from storage same as stock to be placed into storage' is raised in transaction MB1B when trying to transfer...