Error after upgrading from 1.0.2 to 1.0.5

[pgentoo]

at least in Gentoo, this setting is not in a file that is modified by ispcp, and is expected to be set up by the system administrator.

In my case it is /etc/apache2/modules.d/00_default_settings.conf

If this is not a file modified by the ispcp installer, you'll need to manage the index settings yourself.