Users of Microsoft Windows 10 are reporting crashes following this month's tranche of bug fixes and updates to the operating system - reportedly caused, ironically, by the patch intended to stop repeated crashes in Windows 10.
However, it appears that something buried in this month's Patch Tuesday is now stopping machines from booting after the update has been installed.
Windows Latest reports that KB4103721 is the culprit, causing a black screen which freezes. In one of Redmond's more ironic moves, this was the patch that was designed to fix the freezes caused by the update, which Microsoft was forced to delay because of the blue screen of death (BSOD) issues it was causing in beta.
The issue isn't impacting all systems, but if you do happen to be one of the lucky ones affected, you should be able to boot into safe mode and return the system to before the point in which the bothersome bucket of bug fixes was installed.
Microsoft hasn't officially acknowledged the problem - yet - so any advice you take, you do so at your own risk.
Another alternative would be a refresh install from a USB stick, provided you have a second, non-borked machine to make a USB stick OS image. That, though, could jeopardise valuable data.
Apart from anything else, any attempts to reinstall Windows will probably involve you having to reinstall all your apps and that won't be much fun, either.
We certainly don't want to blame the Insider Program, in which all the bugs in the bug fixes should have been debugged - by ordinary users rather than Microsoft-employed software testers.
But the recent poor rollout of patches to Windows-as-a-Service suggests that they are not being as rigorously tested as they should be, and some serious hardware issues are passing through the process undetected.
Last week, Microsoft and Dell were forced to stop the April Update rolling out on Alienware machines, due to various borkage issues.
HP and Centrica are the first industry partners to sign up to the government's new Code
New ice grows faster but is also more vulnerable to weather and wind
With a crackdown on cheats is coming in November, PUBG rushes to fix matchmaking problems introduced in Update #22
New material uses carbon dioxide from the air to repair and reinforce itself