[HOWTO] fix, repair flatpak keyring error [Solved]

[Sigi]

A flatpak issue occured after apt update && apt dist-upgrade -y
Running system: MX 19.4

Result: flatpak apps no more working & MX Package Installer, Flatpaks empty, no more apps visible there.

Solution:

flatpak update --ostree-verbose
> shows errors like above

sudo apt reinstall gnome-keyring
> Done

flatpak update --ostree-verbose

> Looking for updates…
> F: Adding GPG keyring data from flathub.trustedkeys.gpg to verifier
> Nothing to do.

voilà!