It looks like its going to /admin/groups/admin/group/-types/one which probably is not correct. Some of the slashes are URLencoded which is defnitely wrong. I suspect somehwere a return_url query parameter got messed up.
Note those group admin pages are rarely/never used and most groups are created programatically. It should do what you want if you create it through the web UI, but if its a commmon thing you'll need to do, you might want to look into a way to automate it with a subsite or package instantiation callback.