Microsoft has released an important out-of-band (OOB) update which resolves an issue that was leading to app installation failures from the Microsoft Store with an error code "0xC002001B". The issue was arising after installing the KB5011831 Windows 10 build.
Microsoft has determined that the issue was plaguing modern Intel and AMD CPU systems which supported the Intel Control-flow Enforcement Technology (CET) or the AMD equivalent Shadow Stack technology (via TechBeezer). CET helps to mitigate Return-oriented Programming (ROP) exploits or CALL/JMP-oriented programming (COP/JOP) exploits.
The affected CPUs include Intel 11th Gen Tiger Lake chips, as well as 12th Gen Alder Lake CPUs. On the AMD side, the Zen 3 Ryzen 5000 and the latest Zen 3+ Ryzen 6000 series CPUs are affected.
The Microsoft advisory says:
After installing KB5011831 or later updates, you might receive an error code: 0xC002001B when attempting to install from the Microsoft Store. Some Microsoft Store apps might also fail to open. Affected Windows devices use a processor (CPU) which supports Control-flow Enforcement Technology (CET), such as such as 11th Gen and later Intel® Core™ Processors or later and certain AMD processors.
Resolution: This issue was resolved in the out-of-band update KB5015020.
To download the OOB update KB5015020 which fixes this issue, head over to the Microsoft Update Catalog page at this link.