ORA-00904: "DECISION_DTTM_GER": invalid identifier

While upgrading the tools version from 8.46 to 8.50 we are facing a issue while altering table.

SQL> ALTER TABLE PS_UPG_HRS_AP_AET MODIFY

  2 (

  3 DATETIME_STAMP TIMESTAMP(6),

  4 DECISION_DTTM_GER TIMESTAMP(6),

  5 LASTUPDDTTM TIMESTAMP(6)

  6 )

 7 ;

DECISION_DTTM_GER TIMESTAMP(6),

*

FOUT in regel 4:

.ORA-00904: "DECISION_DTTM_GER": invalid identifier.

We are not able to find the DECISION_DTTM_GER in application designer itself.

please provide us details about which version this record and field got added to peoplesoft. Any information on this would do help us to proceed further.