I think already give answer of your question.
Repeat that answer here,
This is due to your id (one space is in your id ) so, if you see your rss feed link then you observe your id in it. Your id in link with + sign ( due to space ) so, due to + sign Feedcat.net not accept your feed because this link not according to their rules.
So, copy your rss link & make it tiny through tinyurl(dot)com, now insert this tiny url in feedcat.net.
Voila they accept your rss feed link.
This trick work 100% because I do this experiment already with your rss feed link.