Microsoft and Symantec have identified an issue that occurs when a device is running any Symantec or Norton antivirus program and installs updates for Windows that are signed with SHA-2 certificates only. The Windows updates are blocked or deleted by the antivirus program during installation, which may then cause Windows to stop working or fail to start.
Microsoft has temporarily placed a safeguard hold on devices with an affected version of Symantec Antivirus or Norton Antivirus installed to prevent them from receiving this type of Windows update until a solution is available. We recommend that you do not manually install affected updates until a solution is available.
Guidance for Symantec customers can be found in the Symantec support article.
