This format of the generic indexer is not anymore. It was deprecated around CMOD 7.1.
And it was removed completely with CMOD 9.X. Maybe it was removed with 8.5.0.6+. But I'm not sure...
In all cases, first try to upgrade to version 8.5.0.10, and test it again.
Then if even with the latest FP from 8.5 it doesn't work, thenopen a PMR for your version 8.5.
In all cases, I would more than strongly suggest to begin now the change to the new format, because you'll need to do it anyway...
Kind regards,
Alessandro