Possible Duplicate:
Auto-Link-validator marks punycode URLs are invalid
I just noticed this question, which contains no links, has a comment from Community♦ indication a broken link in the question.
The closest thing to a link is the image, but the image loads fine.
The post has not been edited since the comment appeared. Did the image trip up the broken link detection, or did something else go wrong here?
Additionally occurs in this answer.
http://unicorn.ü-wie-geek.de/donkey.png
), it's probably the same problem as noted here.