The error occurs when changing expired password after database upgrade to 12cR2.
Cause:
The SQL client used in Forms 11.1.1.x is not supported against the 12.2.x database
Solution:
Upgrade the forms to 12c release which uses newer SQL client which is compatible with 12cR2 database.
Cause:
The SQL client used in Forms 11.1.1.x is not supported against the 12.2.x database
Solution:
Upgrade the forms to 12c release which uses newer SQL client which is compatible with 12cR2 database.