title: Realm Mobile Database and install via packagecloud.io
body: <p>The repository '<a href="https://packagecloud.io/realm/realm/linuxmint" rel="nofollow noreferrer">https://packagecloud.io/realm/realm/linuxmint</a> serena Release' does not have a Release file.
  N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
  N: See apt-secure(8) manpage for repository creation and user configuration details.</p>