List & Label 29 PDF export fails in .NET 8 Docker container on Alpine with "Platform not supported"

The important point here is that List & Label 29 is not the right product/runtime for this scenario.

With List & Label 29 you are using the classic Windows/.NET deployment. The fact that the project compiles in a Linux container does not mean that the required native runtime components are available or supported there. The failure only during PDF export is typical for this kind of problem: the managed .NET code loads fine, but the export eventually needs native List & Label functionality, and that runtime is not available for the platform.

The supported approach for running List & Label in Linux/Docker scenarios is List & Label Cross Platform (LLCP). This is available starting with List & Label 31.

In practice this means:

1. Upgrade to List & Label 31 or newer.
2. Use the LLCP runtime/API, not the classic Windows List & Label deployment.
3. Use a supported Linux base image. Alpine is fully supported, see the LLCP docs.
4. Install the native dependencies required by the LLCP runtime, according to the documentation linked above.

So the problem is not caused by C# or .NET 8 itself. It is a runtime/platform support issue. The application can compile because the .NET references are present, but the export fails when List & Label needs functionality that is not available in that Linux/Alpine environment. Unfortunately, there is no solution for the version 29 you're mentioning. You need to use List & Label 31 or newer with LLCP. Do not try to run the classic List & Label 29 deployment in an Alpine Linux container. For AWS/Docker/Linux PDF export, switch to LLCP and use a supported Linux base image with the documented native dependencies installed. You can trial LLCP by installing the corresponding NuGet package.