My RSS reader stopped working today. When I went to debug it, I saw cloudflare was asking if I was human. Did you intend to block bots on the RSS feeds?
There was probably a high influx of bots on NU today, so Tony had to increase the security of the Cloudflare settings to block them from harming the experience of normal users. Your issue was probably a side effect of this change. Regardless, he'll probably lower the Cloudflare Security Settings after a few days/weeks, but I'm gonna guess your reader will stay broken until then.
if you're on pc, Feed Demon should work. in fact i just tested it using my mobile connection, and it still seems to work (i'm using it as my secondary RSS reader, in case my primary one somehow failed) http://www.feeddemon.com/
The RSS issue has been fixed but the bad news is you'll have to update your RSS feeds. Please go get your new RSS feed links from https://www.novelupdates.com/reading-list/ Sorry but I had to change the URL cause I had issues with Cloudflare