Restore .NET 8 LTS Support for UA-.NETStandard Stack

[BoBiene]

Type of issue

• Bug
• Enhancement
• Compliance
• Question
• Help wanted

Current Behavior

With the introduction of .NET 9 support in PR #2865, .NET 8 support has been removed. This is problematic as .NET 8 is the current Long-Term Support (LTS) framework. Additionally, the .NET 9 assemblies are not backward-compatible, leaving users relying on LTS policies without a supported option.

Expected Behavior

.NET 8 support should be retained alongside .NET 9 to ensure compatibility with LTS requirements, especially for industrial applications where LTS frameworks are mandated by organizational policies.

Steps To Reproduce

1. Update the project to use .NET 8.
2. Attempt to use the current UA-.NETStandard stack.
3. Observe that .NET 8 is no longer supported, resulting in build failures or runtime issues.

Environment

- OS:
- Environment:
- Runtime:
- Nuget Version:
- Component:
- Server:
- Client:

Anything else?

No response

[perclausen]

Fully agree, below just to picture the issue with OPCFoundation.NetStandard.Opc.Ua.Core that references v9.0.0 of Microsoft.Extensions.Logging.Abstractions for .NET 8.

For .NET 8, OPCFoundation.NetStandard.Opc.Ua.Core must reference v8.0.0 of Microsoft.Extensions.Logging.Abstractions like .NET 6 version references v6.0.4 of Microsoft.Extensions.Logging.Abstractions.

[mregen]

According to Nuget.org, logging.abstractions 9.0 supports all other frameworks including net8.0: https://www.nuget.org/packages/Microsoft.Extensions.Logging.Abstractions/#dependencies-body-tab

[perclausen]

According to Nuget.org, logging.abstractions 9.0 supports all other frameworks including net8.0: https://www.nuget.org/packages/Microsoft.Extensions.Logging.Abstractions/#dependencies-body-tab

True, but you are still forcing users to bump Microsoft.Extensions.Logging.Abstractions and all related dependencies to 9.0.0.
Currently this blocks us from upgrading from 1.4.372.56 to 1.5.374.158 because we need to stick with the .NET 8 LTS versions.

Like @BoBiene mentions, we develop industrial applications where can't just bump dependencies at will.