DLLNotFoundException (32/64 bits problem with the DLL probably)

[JomanjiPT]

System information

• OS version/distro: windows 10 (64 bits) and windows server 2012 R2 (64 bits)
• .NET Version (eg., dotnet --info): .Net Framework 4.7.2

Issue

• What did you do? I copied the project from my computer (windows 10) to a server (windows server 2012 R2) and I started to have problems with "DLLNotFoundException".

• What happened? When I copy the project from my computer ( ...\Desktop\ICN) to the server, the path of the project became "\nameOfServer...\ICN" (the Network Path) and when I debug, on my computer (windows 10), that same project I get "DLLNotFoundException".

• What did you expect? I expected to run on the two computers equaly.

Source code / logs

As a side note, my solution has 3 projects: "DataCollection", "RS_WebApp" (where is the method that uses ML.NET) and "NetworkGraph".

Image of the problem:
https://imgur.com/a/SMBmPPW (first image)

My projects it's on "Any CPU" when I debug and with the project, ASP.NET Web Application (.NET Framework), "RS_WebApp" on 64 bits that ML.NET requires and the other 2 projects on "Any CPU".

https://imgur.com/a/SMBmPPW (second image)

I am using the "mlContext.Recommendation().Trainers.MatrixFactorization(options)" and when I build the application it generates the "MatrixFactorizationNative.dll" on "\ICN\RS_WebApp\bin".

The only way that I put to work fine, when debug, was putting this dll on the "C:\Windows\SysWOW64" (in my computer) (ML.NET requires 64 bits) but the problem is that it doesn't work when it's the server calling that method because it doesn't have that file in its folder "C:\Windows\SysWOW64" (or similar to that in windows server) and I can't put that file in the server.

I already tried to put the dll on the project with "Copy to Output Directory: Copy if newer" and it didn't work.

https://imgur.com/a/SMBmPPW (third image)

I also put manually the dll on "\ICN\RS_WebApp\bin\x64" and it didn't work.

I also tried to "Add Reference" on the project (that have the web service with the web method that calls ML.NET "RS_WebApp") the dll but this error happen.

https://imgur.com/a/SMBmPPW (fourth image)

I don't know what folder I can put the dll on, to correctly load that dll.

My thoughts on this are the following:

• something related with debugging a solution with 1 project 64 bits and 2 projects 32 bits, and it "misses" where was the dll for the 64 bits project.
• ML.NET (web API) can have some problem with files in a computer and running on other.

If you need more information, feel free to ask, and a huge thanks if someone can address this problem.

[JomanjiPT]

RS_WebApp.zip
Here, It goes the .csproj of the project that have that issue.
I already read like over 50 stackoverflow and github discussions, and I can't find a solution to this problem. I will be much appreciated if someone can help with this pls.

[veronicaorozco]

Hola, tengo el mismo problema, lo lograste solucionar?

[JomanjiPT]

I had to put the "MatrixFactorizationNative.dll" into the "C:\Windows\SysWOW64" of the server (windows server 2012 R2).

[antoniovs1029]

Hi, @JomanjiPT since you've found the solution for your problem I will close this issue. Please, feel free to reopen it if you're still having problems with this. Thanks!

[admin131]

@JomanjiPT Yours fix didn't work on Windows Server 2016 Standard (64 bits). Do You have any other good idea? :)

[elyasaf755]

I have ran my app on "x64" instead on "Any CPU" and it fixed the problem.
See the following thread for more explanations:
#3764