Solution : https://service.sap.com/sap/support/notes/494969 (SAP Service marketplace login required)
Key words :
error message co888, project planning board, attached program correction, planning board, program error, entry correction, internal error, activity number, table section, column 'id'
Related Notes :
| 556420 | CJ2B:Activity number change in the table area |
| 555534 | CJ2B: Changing activity element number in table section |