I was trying to install gnome builder as instructed in this article https://flathub.org/apps/details/org.gnome.Builder but the flatpak installation failed with following error:
Failed to install org.gnome.Sdk/x86_64/3.30: While pulling runtime/org.gnome.Sdk/x86_64/3.30 from remote flathub: Peer failed to perform TLS handshake
any help?
The problem got solved once I connected my router cable directly to the pc, without the Wifi. Still i believe some bug may be present with the flatpak download manager.