With the latest update of flatpak (currently 1.16.6-r1), flatpak is unable to run and launch apps properly. When any flatpak command is run in the terminal, the following is output:
error: While opening repository /var/lib/flatpak/repo: opening repo:
openat(config): No such file or directory
This is an issue with a change to how the flatpak repo folder is handled. Until a fix is found upstream, a workaround is to clear the repository info by running the following in a terminal:
sudo rm -r /var/lib/flatpak/repo