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I installed flatpak using
$ sudo pacman -S flatpak
after that i a added repo
$ flatpak remote-add --if-not-exists flathub https://dl.flathub.org/repo/flathub.flatpakrepo
and it gives me error
"Unable to load summary from remote flathub: Unacceptable TLS certificate"
i added another following repo
$ flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
this got added without any error but if i install any software from flathub.org it gives me same previous error
"Unable to load summary from remote flathub: Unacceptable TLS certificate"
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Had the same issue. Turned out that my local time was incorrect. The solution was to set correct time
sudo timedatectl set-ntp trueOffline