Rider is stuck on a NuGet restore operation when attempting to load the project

Problem

When attempting to load a project in Rider, it's stuck on nuget restore operation

Resolution

1. Clear NuGet Cache: Run the following command in your terminal to clear the NuGet caches:

   dotnet nuget locals all --clear
   

2. Verify Authentication and Configuration:

   • If your project utilizes private NuGet sources, clear the stored credentials through the Rider Settings interface (Settings | Appearance & Behavior | System Settings | Passwords | Clear).
   • Ensure the PackageReference Restore Engine is configured as either Automatic or Embedded via Settings | Build, Execution, Deployment | NuGet.
   • Restart Rider to initialize fresh authentication prompts.

3. Verify access to nuget.org

   Opening https://www.nuget.org in a browser is not sufficient. NuGet restores use the API endpoint https://api.nuget.org/v3/index.json. From PowerShell, check that the source is configured and enabled:

   dotnet nuget list source

   The output should contain:

    nuget.org [Enabled]
             https://api.nuget.org/v3/index.json
   

   Then test DNS, TCP, and HTTPS access:

   Widows (Powershell):
   Resolve-DnsName api.nuget.org
   Test-NetConnection api.nuget.org -Port 443
   (Invoke-WebRequest -Uri 'https://api.nuget.org/v3/index.json' -UseBasicParsing).StatusCode
   
   Linux/Mac:
   dig +short api.nuget.org
   
   nc -vz -w 10 api.nuget.org 443
   curl -fsSL --max-time 20 -o /dev/null -w 'HTTP %{http_code}\n' https://api.nuget.org/v3/index.json
   
   curl -v --max-time 20 https://api.nuget.org/v3/index.json
   env | grep -iE '^(http|https|all|no)_proxy='
   

   The expected results are a successful DNS lookup, TcpTestSucceeded: True, and HTTP status 200.

   Finally, test an actual package restore in a temporary directory:

   dotnet new classlib --name NuGetConnectivityCheck --output .\NuGetConnectivityCheck --no-restore
   dotnet add .\NuGetConnectivityCheck\NuGetConnectivityCheck.csproj package Newtonsoft.Json --version 13.0.3 --no-restore
   dotnet restore .\NuGetConnectivityCheck\NuGetConnectivityCheck.csproj --source https://api.nuget.org/v3/index.json --force --no-http-cache --packages .\NuGetConnectivityCheck\packages --verbosity normal
   

   A DNS failure, TCP timeout, HTTP 407, TLS/certificate error, NU1301, or TaskCanceledException usually indicates a firewall, proxy, VPN, DNS, or TLS-inspection issue. Contact your IT support for the issue resolution. Provide the failing hostname and error to the network administrator.

Nothing helped

If problems continue after following these steps, contact support and provide the following details for further analysis:

• Screenshot for configurations on Settings | Build, Execution, Deployment | NuGet page
• Rider logs with NuGet tracing enabled:

1. Go to Help | Diagnostic Tools | Choose Trace Scenarios;
2. Enable NuGetAll, NuGetSearch trace scenarios;
3. Reproduce the issue;
4. Share the output in the NuGet toolwindow | Log tab;
5. Collect logs via Help | Collect Logs and Diagnostic Data;
6. Disable the trace scenarios enabled;
7. Upload the logs to the Upload Service and share the Upload ID.