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=bf59a9707a&notice_str=3781073549&hash=a2ac71be64192feb3f5da5a7e28a36c7&redirect_to=https%3A%2F%2Fu.limo%2F14151%2F' caused an error:

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