They changed the URLs for Armoury profiles over two months ago…
They did not update the “View Profile” links from the forums to point to the updated URLs.
Also, if you view the profile of someone that doesn’t play on the US region, you’ll see a page saying there isn’t a profile, but with links to EU and Asia. Those links are also broken as they direct you to a URL with .co in it instead of .com in it, so the link fails.
Then there’s the fact that the Armoury site itself has been broken for at least a month now, where some heroes on an account will display fine, and others will just give “500 internal server error” responses. For once, this doesn’t just appear to be a front-end error, because previously, even when the Armoury site would fail, I could go to d3planner and import my profile, pick a hero, and give a link to that instead. Now when I try to do that, d3planner tells me there’s no profile to import.
Short version: This has been broken for a couple of months and Blizzard seem entirely uninterested in fixing it.