Security enhancements: User session and access management

Hello, 

I Have a problem with Enabling, Security enhancements: User session and access management on my Dynamics CRM 2016 (8.1.1.1005) (DB 8.1.1.1005)

I fallow this manual https://technet.microsoft.com/en-us/library/mt825191.aspx?f=255&MSPPError=-2147217396

I download and installed all required software.

But Scripts:

1. Enable session timeout:

   Run SetAdvancedSettings.ps1 -ConfigurationEntityName ServerSettings -SettingName AllowCustomSessionDuration -SettingValue true

2. Enable inactivity timeout:

   Run SetAdvancedSettings.ps1 -ConfigurationEntityName ServerSettings -SettingName AllowCustomInactivityDuration -SettingValue true

Are Giving me errors:

Get-CrmAdvancedSetting : Source : mscorlib
Method : HandleReturnMessage
Date : 1:28:21 PM
Time : 8/20/2018
Error : Message: The Deployment Service cannot process the request because one or more validation checks failed.
ErrorCode: -2147167645
Stack Trace :
======================================================================================================================
Inner Exception Level 1 :
==DeploymentServiceFault Info==========================================================================================
Error : The Deployment Service cannot process the request because one or more validation checks failed.
Time : 8/20/2018 1:28:21 PM
ErrorCode : -2147167645
Date : 1:28:21 PM
Time : 8/20/2018
Error Items:
VerifyRequestedAtributesAreReadable raising error : One or more of the specified attributes are not valid for retrieve:
AllowCustomSessionDuration
VerifyConfigurationEntityIsNotAmbiquous raising error : Column 'AllowCustomSessionDuration' does not exist on table ServerSettings
======================================================================================================================
At line:1 char:1
+ Get-CrmAdvancedSetting -ConfigurationEntityName ServerSettings -Setti ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidData: (Microsoft.Crm.P...AdvancedSetting:GetCrmAdvancedSetting) [Get-CrmAdvancedSetting], FaultException
`1
+ FullyQualifiedErrorId : CRM Deployment Cmdlet Error,Microsoft.Crm.PowerShell.GetCrmAdvancedSetting

I found that such entry AllowCustomSessionDuration in ServerSetingsProperties in MSCRM_CONFIG does not Exist. But from this Manual should. 

Additionally i MUST remain on this Version.