You may wonder what the heck Level3 is, but it is a major backbone of the Internet based in the US. Many services and even ISPs rely on it to ensure major parts of the world are connected; in fact everything from Yahoo Mail, PSN, Xbox Live, Outlook, BT, Twitch, HBO Go, Craigslist, and other networks and services rely on it.
Level 3 Communications, based in Broomfield, Colorado, provides Internet service via their Tier 1 network to Internet carriers in Europe, Asia, and North America. This means we will currently see problems with a range of services in the UK, Germany, and United States that all use the Level3 network.
Their website is taking a hit right now as services scramble to find out how widespread the outages are, but as we can see from the Down Detector site, and picture above (taken at 14:00 PDT/23:00 CET) the red blotches tell a bleak story.
The company hasn't offered much insight to the outages aside from the above Tweet, but it appears the problems started around three hours ago.
But if you are among the lucky that aren't affected right now, you should be able to complete your download of Windows 10 build 10532.