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=7599b3c128&notice_str=1510593455&hash=4ce760d4f19424a66228a239789b1e79&redirect_to=https%3A%2F%2Fu.limo%2Fpr%2Fpremiere-cc-2017%2F' caused an error:

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