Microsoft late-Monday halted Meltdown and Spectre security patches to machines running AMD processors, as complaints of machines turning unbootable piled up. Apparently the latest KB4056892 (2018-01) Cumulative Update causes machines with AMD processors (well, chipsets) to refuse to boot. Microsoft has halted distributing patches to PCs running AMD processors, and issued a statement on the matter. In this statement, Microsoft blames AMD for not supplying its engineers with the right documentation to develop their patches (while absolving itself of any blame for not testing its patches on actual AMD-powered machines before releasing them).

"Microsoft has reports of customers with some AMD devices getting into an unbootable state after installing recent Windows operating system security updates," said Microsoft in its statement. "After investigating, Microsoft has determined that some AMD chipsets do not conform to the documentation previously provided to Microsoft to develop the Windows operating system mitigations to protect against the chipset vulnerabilities known as Spectre and Meltdown," it added. Microsoft is working with AMD to re-develop, test, and release security updates, on the double.Update (09/01): AMD responded to this story, its statement posted verbatim is as follows.

AMD is aware of an issue with some older generation processors following installation of a Microsoft security update that was published over the weekend. AMD and Microsoft have been working on an update to resolve the issue and expect it to begin rolling out again for these impacted shortly.