I tried switching the mirrors through synaptic then synaptic as usual asked to refresh however the refresh ended with the following errors
W: http://repo.steampowered.com/steam/dists/precise/InRelease: The key(s) in the keyring /etc/apt/trusted.gpg are ignored as the file is not readable by user '_apt' executing apt-key. W: http://security.debian.org/…/dists/stretch/updates/InRelease<http://security.debian.org/debian-security/dists/stretch/updates/InRelease>: The key(s) in the keyring /etc/apt/trusted.gpg are ignored as the file is not readable by user '_apt' executing apt-key. W: http://ftp.de.debian.org/debian/dists/stretch/InRelease: The key(s) in the keyring /etc/apt/trusted.gpg are ignored as the file is not readable by user '_apt' executing apt-key. Any ideas how to resolve that issue? Thank you!
