lib_lightgbm.dll is not getting loaded while running benchmarks on .NetFramework

[Anipik]

when we try to run this https://github.com/dotnet/machinelearning/blob/master/test/Microsoft.ML.Benchmarks/Numeric/Ranking.cs#L50
and
https://github.com/dotnet/machinelearning/blob/master/test/Microsoft.ML.Benchmarks/Text/MultiClassClassification.cs#L47

on .netFramework, the benchmark is not able to load the lib_lightgbm.dll

Unexpected exception: Unable to load DLL 'lib_lightgbm': The specified module could not be found. (Exception from HRESULT: 0x8007007E), 'System.DllNotFoundException'

The benchmarks run properly on .NetCore

cc @danmosemsft @eerhardt @adamsitnik

[danmoseley]

@TomFinley who is the owner of the lightgbm package who can look at this?

[codemzs]

Are you getting this error on other non windows platform? Based on very quick search seems like windows upgrade error. This dll comes from a nuget that is published by @guolinke

[Anipik]

I am getting this error in windows platform. I have not checked it for non-windows platform

[eerhardt]

@Anipik - can you try adding <RuntimeIdentifier>win-x64</RuntimeIdentifier> to your .csproj? By default, no RID is being specified - meaning you are building for "RID-agnostic" or "RID-less". Thus, no native assemblies are being copied from the NuGet packages. Setting win-x64 tells the build system to copy the x64 assemblies to the output folder.

[Anipik]

@eerhardt I tried running it by specifying 64 bit its still not able to find the lighgbm dll

[artemiusgreat]

TL.TR - another way to fix this issue is to install Microsoft Visual C++ Redistributable x64
https://support.microsoft.com/en-ae/help/2977003/the-latest-supported-visual-c-downloads

This is how it happened.

1. Local computer works fine - Windows Pro x64
2. OVH VPS server works fine - Windows Server 2016 x64
3. VULTR VPS doesn't load LightGbm DLL - Windows Pro x64

Tried various combinations of publishing, including Self-Contained deployment with configuration targeting Any CPU, x86, x64, but it didn't run on server #3. Only comparing list of installed programs I noticed that the only missing part on server #3 is MS Visual C++ Redistributable x64. I think I have this update on local computer because I have VS 2019 installed, server #2 is a Server Edition, so probably has this update by default, but server #3 was a custom installation of Windows Pro and it was missing it.