redis enabled but not installed *solved

EDIT on
Problem solved!
The redis php extension was not loaded. Had to put it in my php.ini.

I don't make mistakes, just happy little accidents :-)
EDIT off

I enabled Redis in settings.php and get: redis enabled but not installed
I already deleted /var/lib/redis/dump.rdb and after a restart it was recreated.

Do i need to put something in "auth" in the settings.php?
It is the first time i use Redis but i can connect from my workstation using Keylord (http://protonail.com/products/keylord).

If you want to know:
This is the latest Debian with Nginx, MariaDB, PHP-FPM and HiveMQ running on my Hyper-V 2012R2 Core Server.
Also on this machine (just to swagger a bit):
pfSense router/firewall
FreeSWITCH for telephony and VoIP doorbell
Windows 8.1 with VoxCommando
speech recognition