DSC - module does not exist at the PowerShell module path

Question

This is the error I'm hitting: "The PowerShell provider <module> does not exist at the PowerShell module path nor is it registered as a WMI provider"

I'm not exactly a newbie to PowerShell and DSC, but I'm having a hard time figuring this one out. I have followed the guidance here for troubleshooting. I also found this almost identical question... the only resolution seemed to be rebooting (which I tried).

So I made a configuration which imports a module, OctopusDSC. I left out a lot of parameters during troubleshooting the module import, but here is what I have:

Configuration OctopusServer
{
    Import-DscResource -Module OctopusDSC

    Node "WIN-ABC123" 
    {
        cTentacleAgent OctopusTentacle 
        { 
            Ensure = "Present"
            State = "Started"
            Name = "Tentacle"
            ApiKey = ""
            OctopusServerUrl = ""
            DefaultApplicationDirectory = "C:\Utility"
        }
    }
}

The module exists in C:\Program Files\WindowsPowerShell\Modules both locally and on the server:

C:\>tree "C:\Program Files\WindowsPowerShell\Modules" /f
Folder PATH listing
Volume serial number is 9EC4-62C1
C:\PROGRAM FILES\WINDOWSPOWERSHELL\MODULES
└───OctopusDSC
    │   OctopusDSC.psd1
    │
    └───DSCResources
        └───cTentacleAgent
                cTentacleAgent.psm1
                cTentacleAgent.schema.mof

The module path seems fine (I put carriage returns in at each semi-colon, for readability):

PS C:\> $env:PSModulePath
C:\Users\jasonc\Documents\WindowsPowerShell\Modules;
C:\Program Files\WindowsPowerShell\Modules;
C:\Windows\system32\WindowsPowerShell\v1.0\Modules\;
C:\Program Files\Microsoft Monitoring Agent\Agent\PowerShell

I can call Get-Module:

PS C:\> Get-Module OctopusDSC -ListAvailable

    Directory: C:\Program Files\WindowsPowerShell\Modules

ModuleType Version    Name                                ExportedCommands
---------- -------    ----                                ----------------
Manifest   1.0.1      OctopusDSC                          {Get-TargetResource, Set-TargetResource, Test-TargetResource}

I can call Get-DscResource:

PS C:\temp> Get-DscResource  -Name "cTentacleAgent"

ImplementedAs   Name                      Module                         Properties
-------------   ----                      ------                         ----------
PowerShell      cTentacleAgent            OctopusDSC                     {Name, ApiKey, DefaultApplicationDirectory,...

And this is my error:

PS C:\> Start-DscConfiguration -Path .\OctopusServer -Verbose -WhatIf -Wait
What if: [WIN-ABC123]: LCM:  [ Start  Set      ]
What if: [WIN-ABC123]: LCM:  [ End    Set      ]
The PowerShell provider OctopusDSC does not exist at the PowerShell module path nor is it registered as a WMI provider.
    + CategoryInfo          : InvalidOperation: (root/Microsoft/...gurationManager:String) [], CimException
    + FullyQualifiedErrorId : ModuleNameNotFound
    + PSComputerName        : WIN-ABC123

Am I missing something??

PS C:\> $PSVersionTable

Name                           Value
----                           -----
PSVersion                      4.0
WSManStackVersion              3.0
SerializationVersion           1.1.0.1
CLRVersion                     4.0.30319.34014
BuildVersion                   6.3.9600.16394
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0}
PSRemotingProtocolVersion      2.2

Update

I noticed this problem happens on machines with Microsoft Monitoring Agent installed, but does not happen if that agent is not installed.

After the install, the PSModulePath machine-level environment variable looks like this (split for clarity):

PS C:\> [environment]::GetEnvironmentVariable("PSModulePath","Machine")
C:\Windows\system32\WindowsPowerShell\v1.0\Modules\;
C:\Program Files\Microsoft Monitoring Agent\Agent\PowerShell

If I remove the agent's path, and only leave C:\Windows\system32\WindowsPowerShell\v1.0\Modules\ in there, OctopusDSC is found. I do have to restart WMI Provider Host process to get the environment variable change to take. If I add the path back in... fail.

Now this is confusing to me because the whole time the actual path the module is installed in is C:\Program Files\WindowsPowerShell\Modules, and that is presumbably added to the calculated PSModulePath by PowerShell itself (I assume that because I typically don't see that path set up in the system environment variables).

I have seen elsewhere that duplicating C:\Program Files\WindowsPowerShell\Modules in PSModulePath can cause problems with module resolution. So maybe there are other bugs and sensitivities around it?

I feel like this is kind of an answer, but I am still looking for a workaround, as removing that path is not preferred.

Answer 1

As a sanity check, look at the dir where your .MOF is being created...are there any other MOF files in there? Start-DscConfiguration runs all of the MOF's in a dir. I renamed my MOF file and could not make an error disappear until finally realizing the error was in the old MOF :(

Answer 2

This is a known issue in WMF 4.0. Are you using WMF 4.0? Switching to WMF 5.0 would fix this issue unless you are hitting Windows 10 update patch issue mentioned by Andy.