Likely has to do something with the .NET Core 8 transition. Copied from the release notes:
.NET Adapter — .NET Assembly Execution Support
The .NET adapter now supports .NET 8 for .NET code module execution. You can still execute .NET Framework assemblies using .NET as long as the resources used in the .NET Framework assemblies are present in .NET 8.
Some items and resources are no longer supported. Consult the following list for some support changes and considerations users should take note of when developing with the .NET Adapter and TestStand 2024 Q4:
- The IOConfig step type no longer works with the .NET Adapter. The device drivers are located in the .NET Framework GAC location, and .NET 8 does not support loading assemblies from the GAC.
- Creating remote objects in the TestStand .NET step using the CreateRemoteObject method is no longer supported.
- Calling into the following assemblies is no longer supported:
- GAC assemblies
- .NET assemblies with dependencies on GAC assemblies
- C++/CLI assemblies
- Consider the following when working with .NET assemblies and LabVIEW:
- .NET assemblies called by a VI are not automatically added to TestStand deployments. You must manually add these dependencies to deployments they are used in.
- NET Framework assembly dependencies called by LabVIEW during the execution of a TestStand .NET step must be placed next to these .NET Framework assemblies to prevent runtime execution errors. These dependencies can be found in the LabVIEW installation directory.
- Passing .NET objects between LabVIEW and TestStand is no longer supported.