Solution : https://service.sap.com/sap/support/notes/629115 (SAP Service marketplace login required)
Key words :
numeric user-defined field, change data type cnci_aufk 2, expand customer include ci_aufk, user-defined fields, customer include ci_aufk, table cnci_aufk occurs, customer fields reason, extras -> enhancement category, customer field, enhancement category
Related Notes :
| 607056 | Network: User-defined fields |