How to log in to Microsoft’s websites (MSDN forums, Azure Portal, SharePoint Online) when you get a “Bad Request” error?

This post was most recently updated on April 26th, 2019.Every now and then, something like half of Microsoft’s websites will suddenly stop working – this applies to at least Azure Portal, SharePoint Online sites, MSDN forums, Office Onlineand probably a thousand of other sites. The error is most of the time something like this: Bad Request – Request Too Long HTTP Error 400. The size of the request headers is too long. Or like shown below: Or alternatively, you’re just stuck in a authentication loop … Continue reading How to log in to Microsoft’s websites (MSDN forums, Azure Portal, SharePoint Online) when you get a “Bad Request” error?