We have an old Windows installer custom action that is registering our code signing certificate in the local machine "Trusted Publishers" store during installation. The software installed is an addin for Autodesk Revit, and the reason for the registration is to avoid a startup warning dialog in Revit. The CA uses CertOpenStore() to open the CERT_SYSTEM_STORE_LOCAL_MACHINE and CertAddCertificateContextToStore() for the registration. The code is run on the SYSTEM account during install. This has been working fine for about a decade, but now (beginning in March 2023) on Windows 11 CertAddCertificateContextToStore() has suddenly begun to return access denied (0x80070005). I am suspecting the access rights or needed privileges(?) have changed on Windows 11, but I haven't found anything about this when googling. Does anyone in the community have any insights into this? Regards,