Remote session (wsmprovhost.exe) cannot resolve assemblies due to PowerShellAssemblyLoadContext being initialized with empty basePaths
Author: mariuselixCreated Sep 8, 2026Updated Sep 16, 2026
LabelsIssue-BugNeeds-Triage
Prerequisites
- Write a descriptive title.
- Make sure you are able to repro it on the latest released version
- Search the existing issues.
- Refer to the FAQ.
- Refer to Differences between Windows PowerShell 5.1 and PowerShell.
Steps to reproduce
When running some PowerShell command that needs System.IO.Pipelines remotely (so via wsmprovhost.exe), it fails with a FileNotFoundException, because the file could not be located & loaded into the default ALC (Assembly Load Context). Of course, this could happen with other modules as well.
The file does exist & is in the right place, correct version.
The problem seems to be that the ALC is initialized with string.Empty for basePaths and also specifically System.IO.Pipelines is missing from TRUSTED_PLATFORM_ASSEMBLIES list (raised a separate issue item for that -> https://github.com/PowerShell/PowerShell-Native/issues/114).
https://github.com/PowerShell/PowerShell/blob/b664c2e026d1610e9b5a6cc5b14d3c86aae9ab81/src/System.Management.Automation/utils/ClrFacade.cs#L41
https://github.com/PowerShell/PowerShell/blob/b664c2e026d1610e9b5a6cc5b14d3c86aae9ab81/src/System.Management.Automation/engine/hostifaces/ConnectionBase.cs#L46
https://github.com/PowerShell/PowerShell/blob/b664c2e026d1610e9b5a6cc5b14d3c86aae9ab81/src/System.Management.Automation/CoreCLR/CorePsAssemblyLoadContext.cs#L589
e.g:
PS C:\> Invoke-Command -ComputerName srv-2025.skynet.lab -ConfigurationName powershell.7 -ScriptBlock {
# We need to run something to trigger the loading of System.IO.Pipelines. Interacting with a repository using v3 APIs will trigger it while parsing the JSON (e.g: nuget.org).
Find-PSResource -Name Newtonsoft.Json -Repository NuGet -Verbose
}
Find-PSResource: Could not load file or assembly 'System.IO.Pipelines, Version=10.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The system cannot find the file specified.
Some useful debugging information:
2068206b0e8(System.Management.Automation.PowerShellAssemblyLoadContext)._probingPaths
[raw] 00000206820239d8 System.String[] Length: 0
Run this locally & remotely to confirm:
[pscustomobject]@{
ProcessPath = [Environment]::ProcessPath
BaseDirectory = [AppContext]::BaseDirectory
DepsFiles = [AppContext]::GetData('APP_CONTEXT_DEPS_FILES')
HasPipelinesInTPA = (
[AppContext]::GetData('TRUSTED_PLATFORM_ASSEMBLIES') -split ';'
).Where({ [IO.Path]::GetFileName($_) -eq 'System.IO.Pipelines.dll' }).Count -gt 0
}
LOCAL:
ProcessPath : C:\Program Files\PowerShell\7\pwsh.exe
BaseDirectory : C:\Program Files\PowerShell\7\
DepsFile : C:\Program Files\PowerShell\7\pwsh.deps.json
HasPipelinesInTPA : True
REMOTE:
ProcessPath : C:\Windows\system32\wsmprovhost.exe
BaseDirectory :
DepsFiles :
HasPipelinesInTPA : False
PSComputerName : srv-2025.skynet.lab
This is the flow that leads to the problem:
-> PSResourceGet V3ServerAPICalls
-> System.Text.Json loaded to parse .json response
-> PooledByteBufferWriter from System.Text.Json has a dependency (extends) on PipeWriter, which is coming from System.IO.Pipelines
-> bind System.IO.Pipelines v10.0.0.0 — token cc7b13ffcd2ddd51
-> not in ALC already
-> empty basePaths / __probingPaths
-> not in TRUSTED_PLATFORM_ASSEMBLIES
-> fallback as last resort to legacy GAC / MSIL (not found there either, but not expected to be there anyway)
-> FileNotFoundException
If you manually import the module in the ALC, before running the command, it all works fine. e.g:
Invoke-Command -ComputerName srv-2025.skynet.lab -ConfigurationName powershell.7 -ScriptBlock {
[System.Runtime.Loader.AssemblyLoadContext]::Default.LoadFromAssemblyPath((Join-Path $PSHOME 'System.IO.Pipelines.dll'))
# We need to run something to trigger the loading of System.IO.Pipelines. Interacting with a repository using v3 APIs will trigger it while parsing the JSON (e.g: nuget.org).
Find-PSResource -Name Newtonsoft.Json -Repository NuGetV3Lab
}
GAC Version Location PSComputerName
--- ------- -------- --------------
False v4.0.30319 C:\Program Files\PowerShell\7\System.IO.Pipelin… srv-2025.skynet.lab
Author : James Newton-King
...
Name : Newtonsoft.Json
ProjectUri : https://www.newtonsoft.com/json
...
Expected behavior
The ALC loads System.IO.Pipelines & the command runs successfully.
Actual behavior
Find-PSResource: Could not load file or assembly 'System.IO.Pipelines, Version=10.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The system cannot find the file specified.
Error details
OriginInfo : srv-2025.skynet.lab
Exception :
Type : System.Management.Automation.RemoteException
SerializedRemoteException : System.IO.FileNotFoundException: Could not load file or assembly
'System.IO.Pipelines, Version=10.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The system cannot find the
file specified.
File name: 'System.IO.Pipelines, Version=10.0.0.0, Culture=neutral,
PublicKeyToken=cc7b13ffcd2ddd51'
at System.Text.Json.JsonDocument.Dispose()
at
Microsoft.PowerShell.PSResourceGet.Cmdlets.V3ServerAPICalls.GetJsonElementArr(String request, String propertyName,
Int32& totalHits, ErrorRecord& errRecord) in C:\__w\1\s\PSResourceGet\src\code\V3ServerAPICalls.cs:line 1528
at
Microsoft.PowerShell.PSResourceGet.Cmdlets.V3ServerAPICalls.GetJsonElementArr(String request, String propertyName,
Int32& totalHits, ErrorRecord& errRecord) in C:\__w\1\s\PSResourceGet\src\code\V3ServerAPICalls.cs:line 1498
SerializedRemoteInvocationInfo : System.Management.Automation.InvocationInfo
ErrorRecord :
Exception :
Type : System.Management.Automation.RemoteException
SerializedRemoteException : System.IO.FileNotFoundException: Could not load file or assembly
'System.IO.Pipelines, Version=10.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The system cannot find the
file specified.
File name: 'System.IO.Pipelines, Version=10.0.0.0, Culture=neutral,
PublicKeyToken=cc7b13ffcd2ddd51'
at System.Text.Json.JsonDocument.Dispose()
at
Microsoft.PowerShell.PSResourceGet.Cmdlets.V3ServerAPICalls.GetJsonElementArr(String request, String propertyName,
Int32& totalHits, ErrorRecord& errRecord) in C:\__w\1\s\PSResourceGet\src\code\V3ServerAPICalls.cs:line 1528
at
Microsoft.PowerShell.PSResourceGet.Cmdlets.V3ServerAPICalls.GetJsonElementArr(String request, String propertyName,
Int32& totalHits, ErrorRecord& errRecord) in C:\__w\1\s\PSResourceGet\src\code\V3ServerAPICalls.cs:line 1498
SerializedRemoteInvocationInfo : System.Management.Automation.InvocationInfo
ErrorRecord :
Exception :
Type : System.Management.Automation.RemoteException
SerializedRemoteException : System.IO.FileNotFoundException: Could not load file or assembly
'System.IO.Pipelines, Version=10.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The system cannot find the
file specified.
File name: 'System.IO.Pipelines, Version=10.0.0.0,
Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'
at System.Text.Json.JsonDocument.Dispose()
at
Microsoft.PowerShell.PSResourceGet.Cmdlets.V3ServerAPICalls.GetJsonElementArr(String request, String propertyName,
Int32& totalHits, ErrorRecord& errRecord) in C:\__w\1\s\PSResourceGet\src\code\V3ServerAPICalls.cs:line 1528
at
Microsoft.PowerShell.PSResourceGet.Cmdlets.V3ServerAPICalls.GetJsonElementArr(String request, String propertyName,
Int32& totalHits, ErrorRecord& errRecord) in C:\__w\1\s\PSResourceGet\src\code\V3ServerAPICalls.cs:line 1498
SerializedRemoteInvocationInfo : System.Management.Automation.InvocationInfo
ErrorRecord :
Exception :
Type : System.Management.Automation.RemoteException
SerializedRemoteException : System.IO.FileNotFoundException: Could not load file or
assembly 'System.IO.Pipelines, Version=10.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The system cannot
find the file specified.
File name: 'System.IO.Pipelines, Version=10.0.0.0,
Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'
at System.Text.Json.JsonDocument.Dispose()
at
Microsoft.PowerShell.PSResourceGet.Cmdlets.V3ServerAPICalls.GetJsonElementArr(String request, String propertyName,
Int32& totalHits, ErrorRecord& errRecord) in C:\__w\1\s\PSResourceGet\src\code\V3ServerAPICalls.cs:line 1528
at
Microsoft.PowerShell.PSResourceGet.Cmdlets.V3ServerAPICalls.GetJsonElementArr(String request, String propertyName,
Int32& totalHits, ErrorRecord& errRecord) in C:\__w\1\s\PSResourceGet\src\code\V3ServerAPICalls.cs:line 1498
SerializedRemoteInvocationInfo : System.Management.Automation.InvocationInfo
ErrorRecord :
Exception :
Type : System.Management.Automation.RemoteException
SerializedRemoteException : System.IO.FileNotFoundException: Could not load
file or assembly 'System.IO.Pipelines, Version=10.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The system
cannot find the file specified.
File name: 'System.IO.Pipelines,
Version=10.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'
at System.Text.Json.JsonDocument.Dispose()
at
Microsoft.PowerShell.PSResourceGet.Cmdlets.V3ServerAPICalls.GetJsonElementArr(String request, String propertyName,
Int32& totalHits, ErrorRecord& errRecord) in C:\__w\1\s\PSResourceGet\src\code\V3ServerAPICalls.cs:line 1528
at
Microsoft.PowerShell.PSResourceGet.Cmdlets.V3ServerAPICalls.GetJsonElementArr(String request, String propertyName,
Int32& totalHits, ErrorRecord& errRecord) in C:\__w\1\s\PSResourceGet\src\code\V3ServerAPICalls.cs:line 1498
SerializedRemoteInvocationInfo : System.Management.Automation.InvocationInfo
ErrorRecord : …
Message : Could not load file or assembly
'System.IO.Pipelines, Version=10.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The system cannot find the
file specified.
HResult : -2146233087
TargetObject : Microsoft.PowerShell.PSResourceGet.Cmdlets.V3ServerAPICalls
CategoryInfo : InvalidResult:
(Microsoft.PowerShel…ts.V3ServerAPICalls:V3ServerAPICalls) [Find-PSResource], FileNotFoundException
FullyQualifiedErrorId :
GetResponsesFromRegistrationsResourceFailure,Microsoft.PowerShell.PSResourceGet.Cmdlets.FindPSResource
ScriptStackTrace : at <ScriptBlock>, <No file>: line 32
Message : Could not load file or assembly 'System.IO.Pipelines,
Version=10.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The system cannot find the file specified.
HResult : -2146233087
TargetObject : Microsoft.PowerShell.PSResourceGet.Cmdlets.V3ServerAPICalls
CategoryInfo : InvalidResult:
(Microsoft.PowerShel…ts.V3ServerAPICalls:V3ServerAPICalls) [Find-PSResource], FileNotFoundException
FullyQualifiedErrorId :
GetResponsesFromRegistrationsResourceFailure,Microsoft.PowerShell.PSResourceGet.Cmdlets.FindPSResource
ScriptStackTrace : at <ScriptBlock>, <No file>: line 32
Message : Could not load file or assembly 'System.IO.Pipelines,
Version=10.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The system cannot find the file specified.
HResult : -2146233087
TargetObject : Microsoft.PowerShell.PSResourceGet.Cmdlets.V3ServerAPICalls
CategoryInfo : InvalidResult: (Microsoft.PowerShel…ts.V3ServerAPICalls:V3ServerAPICalls)
[Find-PSResource], FileNotFoundException
FullyQualifiedErrorId :
GetResponsesFromRegistrationsResourceFailure,Microsoft.PowerShell.PSResourceGet.Cmdlets.FindPSResource
ScriptStackTrace : at <ScriptBlock>, <No file>: line 32
Message : Could not load file or assembly 'System.IO.Pipelines, Version=10.0.0.0,
Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The system cannot find the file specified.
HResult : -2146233087
TargetObject : Microsoft.PowerShell.PSResourceGet.Cmdlets.V3ServerAPICalls
CategoryInfo : InvalidResult: (Microsoft.PowerShel…ts.V3ServerAPICalls:V3ServerAPICalls)
[Find-PSResource], FileNotFoundException
FullyQualifiedErrorId :
GetResponsesFromRegistrationsResourceFailure,Microsoft.PowerShell.PSResourceGet.Cmdlets.FindPSResource
ScriptStackTrace : at <ScriptBlock>, <No file>: line 32
Message : Could not load file or assembly 'System.IO.Pipelines, Version=10.0.0.0,
Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The system cannot find the file specified.
HResult : -2146233087
TargetObject : Microsoft.PowerShell.PSResourceGet.Cmdlets.V3ServerAPICalls
CategoryInfo : InvalidResult: (Microsoft.PowerShel…ts.V3ServerAPICalls:V3ServerAPICalls) [Find-PSResource],
FileNotFoundException
FullyQualifiedErrorId :
GetResponsesFromRegistrationsResourceFailure,Microsoft.PowerShell.PSResourceGet.Cmdlets.FindPSResource
ScriptStackTrace : at <ScriptBlock>, <No file>: line 32
Environment data
$PSVersionTable inserted in the ScriptBlock. I cannot test with PowerShell 7.7 preview, because it does not come with a pwrshplugin.dll & PSSessionConfiguration.
Nevertheless, the problematic code is present in the latest master branch.
Name Value
---- -----
Platform Win32NT
PSRemotingProtocolVersion
PSEdition Core
OS Microsoft Windows 10.0.26100
PSVersion 7.6.5
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0…}
GitCommitId 7.6.5
WSManStackVersion 3.0
SerializationVersion 1.1.0.1
Visuals
Failing:
Working, if you manually load the module in the default ALC:
Source: PowerShell/PowerShell