asp.net mvc - Unable to install packages using dotnet add package

Question

I'm a .NET newbie using VS Code while following an online course on Angular and .NET Core. The course requires the AutoMapper.Extensions.Microsoft.DependencyInjection package to be installed but I keep getting the following errors when I try install any package.

• Unable to resolve <package_name> for '.NETCoreApp,Version=v2.2'

• Package <package_name> is incompatible with 'all' frameworks in project <csproj_path>

I use the following command to install the package:

dotnet add package AutoMapper.Extensions.Microsoft.DependencyInjection

What I've tried so far:

1. Added PackageReference manually into the .csproj file then using dotnet restore - results in the same error (NU1100)
2. Cleared the NuGet package cache using dotnet nuget locals all --clear - results in the same error

It was working before when I tried to install the Microsoft.EntityFrameworkCore.Sqlite package at the beginning of the course and now for some reason I can't install any package.

Do note that I'm not able to use the NuGet extension as it's not working behind a corporate proxy.

Any help would be greatly appreciated :)

Answer 1

I finally fixed the issue by deleting the NuGet.Config file in C:Users<user>AppDataRoamingNuGet folder then running dotnet restore

Running dotnet restore created a fresh config file on the folder which i noticed has a different packageSources value than the old one.

The old one had https://www.nuget.org/api/v2/ while the new one had https://api.nuget.org/v3/index.json

I completely forgot that I have VS 2010 (with nuget) installed which was responsible for the old config file and I did not realize that nuget from the dotnet-cli was also using the same old configurations.