Solution : https://service.sap.com/sap/support/notes/887171 (SAP Service marketplace login required)
Key words :
application area com_product_custmsg msgno 028 allowed, system issues error message com_product_custmsg 028, define system message characteristics, cross-application components, missing table entry, original system &2, table entry, t100s table, download categories, sap products
Related Notes :
| 857222 | DNL_CUST_PROD1: Error message COM_PRODUCT_CUSTMSG 028 |
| 369684 | Hierarchy may only be changed in the original system |