From bleepingcomputer.com
Microsoft acknowledged a new known issue leading to Local Security Authority Subsystem Service (LSASS) critical system process crashes and forced reboots on some Windows 10 devices.
LSASS is responsible for security policy enforcing on Windows systems and it is used by the system to add entries to the security log, as well as to handle user logins, password changes, and access token creation.
When LSASS fails, the user will immediately lose access to any accounts available on the machine, an error will be displayed, and the machine is forced to restart.