Raspberry: error while running apt-get update

Hi there,
about half a year ago, I got OpenHAB (IIRC 1.6.x) running on a RaspberryPi. Now, I tried to install the latest version on a new Raspberry.

I’m following this document: http://docs.openhab.org/installation/apt.html

This is what happens (I had to mask the links because of forum restrictions):

The Raspberry is running NOOBS v1.8. Any suggestions?

Thanks in advance!

Have you changed by any means speach and/or keyboard settings from the original to another language or country?

I might have changed the locale settings to Germany while initially setting up, or they were being set automatically. Is there anything you want me to check for in specific?

Has happend also to me.
It took me ages to find out:
Somehow the settings to German language as well as keyboard layout somehow are in contradiction with what the Raspi need to carry out the updates.
I started from scratch but maybe a solution is to change back to the original settings.
Maybe this helps.

There is no folder “stable”, therefore you get a 404 not found error, take a look here:

Maybe this discussion gets you on the right track: