How can I handle htaccess Security Warning?

There is nothing special in my sites-available configuration.
It’s already the same like in the admin manual!

Any ideas?
Does someone need any config files?

I think it is better to open individual topics. Among the posts here were fedora users, debian users, … then perhaps some use admin-interfaces. The probably won’t be a common solution for everybody and with so little information, it is hard to figure out what you actually did and how your system looks like.