Could not load Microsoft.O365.Security.Native.ETW in C# .NET 6.0

[gleen-code]

Hi,

I am using C# with the .NET 6.0 framework and trying to use the NuGet Microsoft.O365.Security.Native.ETW package (https://www.nuget.org/packages/Microsoft.O365.Security.Native.ETW/).

Although all the dependencies are resolved and the library is installed correctly, at run it says that it cannot load the library. This is the exception:

System.IO.FileNotFoundException
  HResult=0x80070002
  Message=Could not load file or assembly 'Microsoft.O365.Security.Native.ETW, Version=1.0.8668.31639, Culture=neutral, PublicKeyToken=31bf3856ad364e35'. The system cannot find the file specified.
  Source=MyProject

Inspecting the library dependencies, in the folder where it has been compiled, I can see that ijwhost.dll is not found.

Although the dependency is located in the same directory, in the following path: runtimes\win-x64\native\Ijwhost.dll

This is the directory bin\Debug\net6.0-windows7.0 structure:

• [My project files]
• Microsoft.O365.Security.Native.ETW.dll
• runtimes\win-x64\native
  • Ijwhost.dll

If I change the .NET framework version to 5.0, everything works fine. Above 6.0, it does not work with any version. Any ideas?

[swannman]

A bit of background:

• C++/CLI code needs to reference Ijwhost.dll at runtime in order to start up the .NET Core runtime. Here are a few references re: ljwhost.dll: [1], [2].
• We followed this guidance to include it in the runtimes\win-x64\native\ directory.
• Unfortunately. DLLs from the \runtimes\ directory aren't automatically copied to the output directory unless you do a dotnet publish. More on that behavior here and here.

The best way we've found to get the DLL into the output directory is to edit the .csproj file and add an msbuild copy step:

<ItemGroup>
<PackageReference Include="Microsoft.O365.Security.Native.ETW" Version="4.3.2">
      <GeneratePathProperty>true</GeneratePathProperty>
    </PackageReference>
</ItemGroup>

<Target Name="CopyFiles" AfterTargets="Build">
<ItemGroup>
<File Include="$(PkgMicrosoft_O365_Security_Native_ETW)\runtimes\win-x64\native\Ijwhost.dll"></File>
</ItemGroup>
<Copy SourceFiles="@(File)" DestinationFolder="$(OutDir)"></Copy>
</Target>

Want to give this a try and let us know whether it works?

[gleen-code]

Thank you very much, @swannman. That's works and makes sense.

I think you should document this, I've found more people with the same issue, and it's not very intuitive to solve.