Hi Andrew,
I did not change much to the sample ;-).
I copied the directory "C:\Users\Public\Documents\AlterNET Software\AlterNET Studio v.6" to "C:\Temp\AlterNET Studio v.6_modified", opened the solution "AlterNET.Studio.AllDemos.sln", and modified the settings in project "SnippetsParser": I unchecked the checkbox "Auto-generate binding redirects", see screenshot "changedsetting.png".
This results in the above mentioned warning.
Screenshot and detailed build log can be found in https://www.hg-online.de/downloads/AlterNetReferencesWarning.zip
On my machine, I have the latest Visual Studio update 16.5.4, and hopefully the latest win updates. Also, AlternetStudio 4.0, 5.1 and 6.0 are installed.
It seems some references e.g. ("netstandard") are resolved to "C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\MSBuild\Microsoft\Microsoft.NET.Build.Extensions\net461\lib\netstandard.dll" (AssemblyFileVersion: 4.6.26011.1, AssemblyVersion: 2.0.0.0), while others are picked from nuget packages.
In our "real" project, we did not use NuGet, but I copied the AlterNet files locally, and all other references are resolved to the locally installed Framework.
Best regards
Wolfgang