Solution : https://service.sap.com/sap/support/notes/954148 (SAP Service marketplace login required)
Key words :
newly added field control objects, existing field control settings, customer-specific field control, customer field control, initial generation takes, correspondingly long time, attached correction instructions, generating field control, customizing settings successfully, generating local classes
Related Notes :
1003959 | Field control: Corrections for various errors |
947936 | Setting up field control |