Things happen, eh? In a move that shows how hard it is to escape advertisements these days, an ad from Microsoft was the cause behind all the hoopla where the Windows 11 Taskbar was bricked.
And, as covered here, took down pretty much the whole of the UI — the Start Menu, File Explorer.
It was a promo about how Windows 11 is deeply integrated with Teams.
But apparently, that was enough to crash the desktop shell in the operating system. Microsoft was quick to post a workaround, noting that the problem was caused by a server-side deployment that went out to Windows Insiders testing the upcoming OS.
A little digging revealed that the issue was caused by a small file downloaded by a Windows component that goes by the name of IrisService. Iris is part of Windows Spotlight, and handles duties like lock screen suggestions, Bing wallpaper of the day and all that jazz.
This post over on the Ctrl blog discovered that the problem could be narrowed down to a registry key that contained a serialized JSON blob, which contained the advertisement for Microsoft Teams.
The messaging and imagery in the ad were similar to the panel that you get when a Windows account is not already set up with Teams.
This was what ultimately caused the shell to crash.
For solace, the problem was not caused by an update that Redmond delivered through the Windows Update service. That might have been more understandable, but then again, Windows 11 is pretty solid in this regard.
However, it is clear that the OS was not ready for an advertisement like this.