Recently, Microsoft announced that in Windows 10 v1809 and Windows Server 2019, many hosts will experience device startup failure issues if the UEFI boot option is enabled. In an article by TechNet, Microsoft pointed out that the root cause of this problem is the SystemGuard Launch security boot settings introduced in Windows 10 1809. Enabling these settings will result in a blank screen at boot time.
Microsoft wrote, “Microsoft discovered a boot issue that could affect systems with the System Guard Secure Launch set to enabled regardless of whether the underlying hardware support for the feature is present. The issue manifests itself after taking an update whereupon the device reboots into a blank screen. The issue has been root caused to a problem with catalog file validation and whether it shows up is highly dependent on set and order of signed components in the boot path so it is not predictable when or whether a system will hit this issue.”
Microsoft said that the relevant fixes are under development. During this time, users are advised to “revert the “ConfigureSystemGuardLaunch” Group Policy setting to “Not Configured” or configure it to “Disabled” to alleviate this issue”.