Sometimes a site will not load by default but it works just fine in InPrivate mode or when loaded in a different browser profile. In many such cases, this means there’s a bug in the website where they’ve set a cookie but fail to load when that cookie is sent back.
This might happen, for instance, if a site set a ton of cookies over time but the server has a request length limit. After the cookies build up through the course of normal browsing, the 16k header limit is exceeded and the server rejects all further requests by dropping the connection or showing a message like Bad Request – Request too long, Bad Request – The size of the request headers is too long, or ERR_TOO_MANY_REDIRECTS. This problem is unfortunately common for large web properties, including Microsoft.com.
Fortunately, it’s often easy to fix this problem in the new Edge (and Chrome).
Delete Cookies for the Current Site
On the error page, click the icon next to the address bar and see whether there are Cookies in use:
If so, click the item to open the Cookies in use screen. In the box that appears, select each server name and click the Remove button at the bottom to remove the cookies set for that server:
After you remove all of the cookies, click the Done button and try reloading the page.
PS: If you have a server hitting this problem, use fewer/smaller cookies, and reconfigure your server to accept larger headers. Reconfiguration might be required to use your server if your server uses Active Directory authentication and your visitors have large AD tokens.