Forum Discussion
PowerShell DSC Pullserver stops working with SQL database
After updating Windows Server 2025, our DSC Pull Server stopped communicating with its SQL backend database. The issue was not present before the update, and reverting to the previous version of Microsoft.PowerShell.DesiredStateConfiguration.Service.dll immediately restored normal functionality.
With the newer DLL version, the service starts successfully and the endpoint remains available, but no connection is established to the SQL Server database. As a result, database initialization does not occur, required tables are not created or updated, and node registration fails. No database sessions are observed on the SQL Server during registration attempts, indicating that the service does not reach the SQL connection phase.
We compared the previous working DLL version with the updated version and confirmed that the regression is introduced by the newer DLL. Replacing the updated DLL with the earlier version consistently restores SQL database connectivity and normal Pull Server Operation.
3 Replies
Thank you for providing the additional details. Your troubleshooting is quite thorough, and the A/B comparison is especially compelling.
Since the issue is reproducible across multiple environments and replacing only Microsoft.PowerShell.DesiredStateConfiguration.Service.dll restores SQL connectivity, it appears unlikely that the problem is related to SQL Server, IIS, or the Pull Server configuration itself.
A few additional suggestions that may help narrow this down further:
- Verify that the SQL connection string is still being read correctly after installing KB5087051.
- Enable Failed Request Tracing (FREB) in IIS to capture any exceptions that may not be logged in the standard DSC or Application logs.
- Use Process Monitor (ProcMon) during a node registration attempt to determine whether the updated DLL is failing to load a dependency, access a configuration file, or read a required registry value before attempting the SQL connection.
- If possible, compare the loaded assemblies and configuration between the working (10.0.26100.1) and failing (10.0.26100.5074) versions.
Given that no SQL login attempts or sessions are observed, the failure likely occurs before the SQL client is initialized, which would also explain why no additional errors appear in the SQL Server logs.
At this point, I would recommend opening a Microsoft support case and including:
- Windows Server 2025 build number
- KB5087051
- The working and failing DLL versions
- ProcMon and FREB traces
- A minimal reproducible SQL-backed Pull Server configuration
Based on the evidence you've collected, this appears to be a strong candidate for a regression introduced by KB5087051. It will be interesting to see whether other administrators using SQL-backed DSC Pull Servers can reproduce the same behavior after installing this update.
This appears to be a regression in the newer Microsoft.PowerShell.DesiredStateConfiguration.Service.dll. The Pull Server starts and the endpoint remains available, but no SQL connection is attempted. Database initialization does not occur, tables are not created or updated, and node registration fails.
Replacing only the updated DLL with the previous version immediately restores normal SQL connectivity and Pull Server operation. This strongly indicates that the issue is introduced by the newer DLL and occurs before the SQL connection stage.
The recommended next step is to open a Microsoft support case and include the Windows Server build, installed KB, both DLL versions, and relevant DSC, IIS, and Application logs. The older DLL can be used as a temporary workaround.
Thank you for the feedback.
We have performed additional testing and were able to narrow the issue down further.
The problem occurs with Microsoft.PowerShell.DesiredStateConfiguration.Service.dll version 10.0.26100.5074, which was installed by KB5087051 on Windows Server 2025.
In comparison, the same DSC Pull Server configuration works correctly with Microsoft.PowerShell.DesiredStateConfiguration.Service.dll version 10.0.26100.1 from KB5044030.
When using the newer DLL version, the Pull Server service starts successfully and the endpoint remains accessible, however DSC client registration fails and no SQL database activity is observed. The only error returned during registration is:
Error registering the DSC agent with Agent ID a3ed4889-f77f-11f0-a0f1-00155d646b1c. The underlying error is: "The registration of the DSC Agent with Agent ID = a3ed4889-f77f-11f0-a0f1-00155d646b1c failed. The underlying error is 'UnexpectedError'."
No additional errors are logged in the DSC logs, IIS logs, or Windows Application logs.
As a validation step, we replaced only Microsoft.PowerShell.DesiredStateConfiguration.Service.dll version 10.0.26100.5074 with the previous version 10.0.26100.1 while keeping the rest of the environment unchanged. After doing so, SQL connectivity was immediately restored and DSC client registration succeeded.
We have reproduced this behavior in multiple environments. Based on these results, this appears to be a regression introduced between KB5044030 and KB5087051 affecting SQL-backed DSC Pull Server deployments.
Has anyone else observed similar behavior, or is Microsoft already tracking this as a known issue?
