[SOLVED] "GPG error" when running apt-get update

[Anonymized_GDPR]

Hello

I have googled this but i can't find a solution. When I try to update I get this error:

Terminal

Hit http://archive.raspberrypi.org wheezy Release.gpg
Hit http://mirrordirector.raspbian.org wheezy Release.gpg
Hit http://archive.raspberrypi.org wheezy Release
Hit http://mirrordirector.raspbian.org wheezy Release
Hit http://archive.raspberrypi.org wheezy/main armhf Packages
Hit http://mirrordirector.raspbian.org wheezy/main armhf Packages
Get:1 http://xbian.dehakkelaar.nl/ wheezy Release.gpg [3,639 B]
Hit http://mirrordirector.raspbian.org wheezy/contrib armhf Packages
Get:2 http://xbian.dehakkelaar.nl/ wheezy Release [3,639 B]
Hit http://mirrordirector.raspbian.org wheezy/non-free armhf Packages
Ign mirror://apt.xbian.org wheezy Release
E: GPG error: mirror://apt.xbian.org wheezy Release: The following signatures were invalid: NODATA 1 NODATA 2

I manually deleted http://xbian.dehakkelaar.nl/ from the sources.list a few weeks ago because it was unreachable. Now my sources.list is normal again, but I get this GPG Error.
Furthermore I had these strange dpkg errors. I fixed this with an update which I have found here on the forum.

How can I fix this? I am running 1.0 beta 1.2.

Thanks