4.006 - Users must be forcibly disconnected when their logon hours expire.
Users must not be permitted to remain logged on to the network after they have exceeded their permitted logon hours. In many cases, this indicates that a user forgot to log off before leaving for the day. However, it may also indicate that a user is attempting unauthorized access at a time when the system may be less closely monitored. Forcibly disconnecting users when logon hours expire protects critical and sensitive network data from exposure to unauthorized personnel with physical access to the computer.
Configure the policy value for Computer Configuration -> Windows Settings -> Security Settings -> Local Policies -> Security Options -> 'Microsoft Network Server- Disconnect Clients When Logon Hours Expire' to 'Enabled'.