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=8addc78709&notice_str=3768541241&hash=718f91ce8fdfba5e0f941ab6378608df&redirect_to=https%3A%2F%2Fu.limo%2Ftag%2F%25E4%25BA%25BA%25E5%2590%258D%2F' caused an error:

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