How to correctly use third party DLLs

Hi everyone,

I'm very new with third party assemblies and Unity and that's my first experience with it

I'm currently working on a Unity 2018.2 project in which I need to write into an Excel file

I got 2 main issues :

1 -- I created an Excel file with VSTO, so I got a couple of file :

    Microsoft.Office.Tools.Common.v4.0.Utilities.dll
    Microsoft.Office.Tools.Excel.v4.0.Utilities.dll
    VR Export Workbook.dll
    VR Export Workbook.dll.mdb
    VR Export Workbook.dll.manifest
    VR Export Workbook.pdb
    VR Export Workbook.vsto
    Export.xlsx

Unity cannot load

VR Export Workbook.dll

Unloading broken assembly Assets/Resources/Profils/VR Export Workbook.dll, this assembly can cause crashes in the runtime

What should I do to get rid of this message ?

Also I cannot compile the Unity project without having to manually moved my files, I got this error on build :

ArgumentException: The Assembly Microsoft.VisualStudio.Tools.Applications.Runtime is referenced by VR Export Workbook ('Assets/Resources/Profils/VR Export Workbook.dll'). But the dll is not allowed to be included or could not be found.

I'm not feeling like copy / paste the whole .NET framework assemblies inside my project, what can I do for this ?

2 -- Unity does not export my Resources folder

The whole Excel stuff is located inside my Resources folder, because I want those files to be in the build and editable

I got this folder tree :

Assets/
--- Resources/
      |--- Documentations/ (contains images)
      |--- Lang/ (contains sub folder with JSON files)
      `--- Profils/ (contains my Excel stuff and subfolders)

But nothing is copied on build, even without the Excel VSTO

Any idea ?

Thanks in advance for your replies