There are some mysterios errors on my SharePoint farm. After reading tons of log files I found some hints to problems with the “Session State Service” of SharePoint 2010.
I found this Cmdlets in PowerShell for controlling this service:
Enable-SPSessionStateService
Disable-SPSessionStateService
Get-SPSessionStateService
Set-SPSessionStateService
I tried to enable the service with the first Cmdlet. – This was the resulting error:
Error message: “Microsoft SharePoint Server session state could not find the Session State Service. Contact your farm administrator.”
There is no information about this error in the internet. (Till now 
)
MY SOLUTION FOR MY PROBLEM (may be it does not help you in your special situation. It’s “experimental”!!!):
I created a PowerShell script for re-creating the Session State Service and its Service Application.
Before you go on: Make sure, the Windows service “ASP.NET State Service” is running. (I set it to start automatically during system startup.)
This is the resulting script:
#region Check x64 host
if( [System.IntPtr]::Size -ne 8) {
Write-Error "Please use a x64 PowerShell host!"
return
}
#endregion
#region Load SharePoint SnapIn and DLL
Remove-PSSnapin Microsoft.SharePoint.PowerShell -ErrorAction SilentlyContinue
Add-PSSnapin Microsoft.SharePoint.PowerShell -ErrorAction SilentlyContinue
#Check available SharePoint Cmdlets
if( (Get-Command -Noun SPWeb*) -eq $null ) {
Write-Error "SharePoint SnapIn not loaded. SharePoint cmdlets missing!"
return
}
#endregion
cls
$farm = [Microsoft.SharePoint.Administration.SPFarm]::Local
$services = $farm.get_Services() #get all SharePoint services
$sessionStateService = ($services | ? { $_.TypeName -like "*session state*" } ) #find the existing Session State Service -> it was "NULL" for me!
if( $sessionStateService -eq $null ) {
#Recreate the Service
$newSessionStateService = New-Object Microsoft.Office.Server.Administration.SessionStateService ("", $farm)
$newSessionStateService.Id = [System.Guid]::NewGuid()
$newSessionStateService.Name=[String]::Empty
$newSessionStateService.Update()
$farm.Update()
$newSessionStateService.Provision()
$newSessionStateService.Name=[String]::Empty
$newSessionStateService.Update()
}
$services = $farm.get_Services()
$sessionStateService = ($services | ? { $_.TypeName -like "*session state*" } )
$servers=(Get-SPServer)
#Create service instances on all application servers of the SharePoint farm
$servers | % {
if( $_.Role -eq "Application" ) {
$currentSessionStateSvcOnServer = ($_.ServiceInstances | ? { $_.TypeName -like "*session state*" } )
if( $currentSessionStateSvcOnServer -eq $null ) {
#write-host $_.Name $server.Role $_.gettype().fullname
#To create a service instance you must use a "protected" constructor
[type]$t = "Microsoft.SharePoint.Administration.SPServiceInstance" -as "Type"
$p = @( ("string" -as [Type]), ("Microsoft.SharePoint.Administration.SPServer" -as [Type]),
("Microsoft.SharePoint.Administration.SPService" -as [Type]) )
$c = $t.GetConstructor([System.Reflection.BindingFlags]::NonPublic -bor [System.Reflection.BindingFlags]::Instance,$null, $p, $null)
#these are the parameters for creating a service instance by using the protected constructor
[Object[]]$params = @([Object]"Session State Service Instance",
[Object]([Microsoft.SharePoint.Administration.SPFarm]::Local.Servers[$_.Name]),
[Object]([Microsoft.SharePoint.Administration.SPFarm]::Local.Services[$sessionStateService.Id]))
$newSvcInstance = $c.Invoke($params)
#update & provisioning
$newSvcInstance.Update()
$newSvcInstance.Provision()
}
}
}
if( (Get-SPSessionStateService -ErrorAction SilentlyContinue) -ne $null ) {
Write-Host "Successfull :-)" -ForegroundColor Green
} else {
Write-Host "Failed :-(" -ForegroundColor Red
}
After that, the “Enable-SPSessionStateService” works:
(Spend me 1 1/2 days.)
You can use this script to delete the Session State Service, e.g. if some script parts does not work as expected. ONCE MORE: USE IT CAREFULLY AND AT YOUR OWN RISK!!!
#region Check x64 host
if( [System.IntPtr]::Size -ne 8) {
Write-Error "Please use a x64 PowerShell host!"
return
}
#endregion
#region Load SharePoint SnapIn and DLL
Remove-PSSnapin Microsoft.SharePoint.PowerShell -ErrorAction SilentlyContinue
Add-PSSnapin Microsoft.SharePoint.PowerShell -ErrorAction SilentlyContinue
#Check available SharePoint Cmdlets
if( (Get-Command -Noun SPWeb*) -eq $null ) {
Write-Error "SharePoint SnapIn not loaded. SharePoint cmdlets missing!"
return
}
#endregion
cls
$farm = [Microsoft.SharePoint.Administration.SPFarm]::Local
Get-SPServiceApplication | ? {$_.GetType().FullName -eq "Microsoft.Office.Server.Administration.SessionStateServiceApplication"} | Remove-SPServiceApplication
$farm.Services | ? { $_.TypeName -like "*session state*" } | % {
$_.Instances | % {
$_.Delete()
}
$_.Delete()
}
