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=3228411528&hash=8b46f40b9a1bb106183a603eb09ed191&redirect_to=https%3A%2F%2Fu.limo%2Ftag%2F%25E6%25B0%25B4%25E5%25A2%25A8%25E7%25AC%2594%25E5%2588%25B7%25E5%258F%258C%25E9%2587%258D%25E6%259B%259D%25E5%2585%2589%2F' caused an error:

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