title: Azure DevOps Server pipeline build fails when using self-signed SSL certificate with "unable to get local issuer certificate" during NuGet restore
body: <p>After upgrading to Azure DevOps Server 2019, automated pipeline builds are failing at the NuGet restore step showing:</p>
  
  <blockquote>
    <p>Error: Error: unable to get local issuer certificate</p>
    
    <p>Packages failed to restore</p>
  </blockquote>
  
  <p><a href="https://docs.microsoft.com/en-us/azure/devops/pipelines/agents/certificate?view=azure-devops-2019" rel="noreferrer">Microsoft's documentation</a> states that the build agent running on Windows uses the Windows certificate store, so I have checked that the required certificates are installed correctly on the build server, however it is still failing.</p>
  
  <p>There are many questions with similar symptoms but not the same cause. After investigation, I have found the solution to this but I didn't spot anything on this exact issue so I will post an answer that will hopefully save somebody else some time!</p>