When CLI version of dnf encounters a new GPG key for a repo it offers to import it.
yumex-dnf fails with an error message.
It should have popped up a message window and ask for permission to import the new key.
example from CLI dnf:
warning: /var/cache/dnf/rpmfusion-nonfree-updates-031b4488fbcdfcb3/packages/rpmfusion-nonfree-release-23-0.1.noarch.rpm: Header V4 RSA/SHA1 Signature, key ID 5ca6c469: NOKEY
Importing GPG key 0x5CA6C469:
Userid : "RPM Fusion nonfree repository for Fedora (23) rpmfusion-buildsys@lists.rpmfusion.org"
Fingerprint: 15B9 D223 C819 BF69 86A6 F203 D26D EA72 5CA6 C469
From : /etc/pki/rpm-gpg/RPM-GPG-KEY-rpmfusion-nonfree-fedora-23
Is this ok [y/N]: y
When CLI version of dnf encounters a new GPG key for a repo it offers to import it. yumex-dnf fails with an error message. It should have popped up a message window and ask for permission to import the new key.
example from CLI dnf: