This issue was originally reported on Azure docs

@SamShekhovtsov reported an issue:

Could you confirm that current latest version of the ApplicationInsights 'Microsoft.ApplicationInsights.AspNetCore' v2.12.0 is not compatible with the Core 3.1? When I try to add that library reference, it also adds more than 10 other libraries with older versions, that might conflict with Core 3.1

I was unable to reproduce this in a new web application with default settings.

@GoguX was able to reproduce this:

I was able to reproduce this issue by setting AutoGenerateBindingRedirects = true in the project file and targeting netcoreapp3.1. In my case,
the warnings I get are:

1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Data.SqlClient" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Diagnostics.PerformanceCounter" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.IO.FileSystem.AccessControl" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.

This is just creating a new console application and adding Microsoft.ApplicationInsights.AspNetCore version 2.13.0.