Label project export fails in Web Report Designer (Angular sample, LL31)

You will find the lastest prerelease service pack in general within your combit account for download.

The sample works with the classic List & Label version for Windows. You are mentioning the new cross platform version. I think the packages are updated in another way there - found that:
New NuGet server for LLCP packages

As I remember the installed samples are working with hard references - the assemblies directly from installation directory are used - not the NuGet packages.