Error: 404 Not Found

Sorry, the requested URL 'http://u.limo/wp-admin/admin-ajax.php?channel_id=social_wechat&action=xh_social_channel&tab=login_redirect_to_authorization_uri&xh_social_channel=7814ef69ff&notice_str=6156215682&hash=b2d5d454e82df57d5765a4a66f21be01&redirect_to=https%3A%2F%2Fu.limo%2F%3Fs%3D%25E7%25AB%2596%25E5%25B1%258F' caused an error:

Not found: '/wp-admin/admin-ajax.php'