Ahojte, robil som update svojho Raspbiana podla navodu :
https://www.root.cz/zpravicky/novy-raspbian-zalozeny-na-debianu-stretch/Mam nainstalovane aj Kodi , tak som mu updatol repozitar na :
http://pipplware.pplware.pt/pipplware/dists/stretch/main/binarypredtym som pouzival repozitar :
http://pipplware.pplware.pt/pipplware/dists/jessie/main/binary/Update Raspbiana prebehol v poriadku, ked vsak chcem updatnut SW pomocou apt-get update tak dostanem nasledujucu chybu :
sudo apt-get update
Hit:1
http://mirrordirector.raspbian.org/raspbian stretch InRelease
Hit:2
http://archive.raspberrypi.org/debian stretch InRelease
Get:3
http://pipplware.pplware.pt/pipplware/dists/stretch/main/binary InRelease [2085 B]
Ign:3
http://pipplware.pplware.pt/pipplware/dists/stretch/main/binary InRelease
Fetched 2085 B in 1s (1244 B/s)
Reading package lists... Done
W: GPG error:
http://pipplware.pplware.pt/pipplware/dists/stretch/main/binary InRelease: The following signatures were invalid: 88008C73739ACCF6C6808E03D9A264BCBAA567BB
W: The repository '
http://pipplware.pplware.pt/pipplware/dists/stretch/main/binary InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(

manpage for repository creation and user configuration details.
Skusal som aj nasledujuce prikazy, ktore odporucaju ale bez vysledku :
cd /var/lib/apt
mv lists lists-backup
apt-get clean all
apt-get update
Vypis /etc/apt/sources.list a /etc/apt/sources.list.d/raspi.list :
cat /etc/apt/sources.list
deb
http://mirrordirector.raspbian.org/raspbian/ stretch main contrib non-free rpi
deb
http://pipplware.pplware.pt/pipplware/dists/stretch/main/binary /
cat /etc/apt/sources.list.d/raspi.list
deb
http://archive.raspberrypi.org/debian/ stretch main ui