3216067 - DDL Source P_SPECAPICUSTOMDEFINEDATTRIB could not be activated in ACT_UPG phase

During an EHP upgrade, in phase MAIN_SHDRUN/ACT_UPG, the following error is raised:

1EEDO519X"DDL Source" "P_SPECAPICUSTOMDEFINEDATTRIB" could not be activated
1 ETP111 exit code           : "8"

Upon further checking of this DDL source, the error is displayed:

1 EDO578XThe following errors or warnings have occurred:
1EEDO519X"DDL Source" "P_SPECAPICUSTOMDEFINEDATTRIB" could not be activated
1 ED0313 (E- Key fields are not together at the beginning of the view )

S/4HANA systems

SAP NetWeaver

DDL Source, DDLS, P_SPECAPICUSTOMDEFINEDATTRIB, SUM, Upgrade, SNOTE, ACT_UPG , KBA , BC-DWB-DIC-AC , ABAP Dictionary Activation and Conversion , BC-UPG-TLS-TLA , Upgrade tools for ABAP , Problem