404. That’s an error.
The requested URL /add?source=atgs&feedurl=http%3A%2F%2Fwww.rp-online.de%2Fsport%2Fmotorsport%2Ffeed.rss was not found on this server. That’s all we know.
/add?source=atgs&feedurl=http%3A%2F%2Fwww.rp-online.de%2Fsport%2Fmotorsport%2Ffeed.rss