error NU1301: Unable to load the service index for source https://api.nuget.org/v3/index.json

I was running a docker build against a .NET Web API project, on a Windows OS machine connected to a VPN and I was getting the error error NU1301: Unable to load the service index for source https://api.nuget.org/v3/index.json.

This fixed it for me…

  • Open Docker Desktop
  • Click the Settings button
  • Click on the Docker Engine option
  • Add a dns section to the JSON configuration, i.e. 
    {
  "dns": [
      "8.8.8.8"
  ],
  "experimental": false
}