I am trying to create a .dll file using C# and then execute the function in Python using pythonnet. However, I am encountering the following error:

System.TypeLoadException: Could not load type 'System.IO.Directory' from assembly 'System.Runtime, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'.

Environment:

Pythonnet = 3.x

Python = 3.9

NET = 7.0

.csproj

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net7.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
  </PropertyGroup>

  <ItemGroup>
    <Reference Include="FLEXlm_C_sharp">
      <HintPath>FLEXlm_C_sharp.dll</HintPath>
    </Reference>
  </ItemGroup>

  <Target Name="CopyLicDllAfterBuild" AfterTargets="Build">
    <Exec Command="xcopy "$(ProjectDir)lmgr11_64.dll" "$(TargetDir)" /Y /I" />
  </Target>
  <Target Name="CopyLicDllAfterPublish" AfterTargets="Publish">
    <Exec Command="xcopy "$(ProjectDir)lmgr11_64.dll" "$(PublishDir)" /Y /I" />
  </Target>
</Project>

Python

import clr
import os

dll_directory = "./"
clr.AddReference(os.path.join(dll_directory, "LicenseService_Dll.dll"))
clr.AddReference(os.path.join(dll_directory, "FLEXlm_C_sharp.dll"))

from Verifai.Infra.Service.Repository import FlexlmLicenseService
license_service = FlexlmLicenseService()
directory_path = r"D:LicenseServicepythonDll"
status = license_service.CheckOutUsingLicenseSettings(directory_path)

I am encountering the error: ‘Could not load type “System.IO.Directory” from assembly “System.Runtime, Version=4.0.0.0″‘.

Any help to resolve this issue would be greatly appreciated.