I tried again today at 12:32 a.m. ET (New York)
I entered https://gnusocial.net/group/gnusocial as the field to join remote group
I was given the option to confirm joining remote group, when I did I get error "Remote group join failed!"
FYI gnusocial.jp is a social network, courtesy of GNU social JP. It runs on GNU social, version 2.0.1-beta0, available under the GNU Affero General Public License.
@gnusocialjp uhm, there's women on there for one thing. and they are looking seductive. There's an option in the SETTINGS menu for uploading a background image, but when I try to it seems to sit there forever. https://gnusocial.jp/url/245615