The error message "An error occurred while trying to restore packages. The underlying connection was closed: An unexpected error occurred on a send" typically indicates an issue with the network connectivity or configuration. Here are a few suggestions to resolve this error:
Check network connectivity: Ensure that your internet connection is stable and working properly. Try accessing other websites or online resources to verify your network connectivity.
Disable firewall or antivirus: Temporarily disable any firewall or antivirus software that might be blocking the network connection. Sometimes, security software can interfere with the package restoration process.
Use a different network: If possible, try switching to a different network, such as a different Wi-Fi network or a mobile hotspot. This can help determine if the issue is specific to your current network configuration.
Configure proxy settings: If you are behind a proxy server, ensure that the proxy settings are correctly configured in your development environment. Update the proxy settings in tools like NuGet Package Manager or Visual Studio to match your network configuration.
Clear package cache: Delete the NuGet package cache on your machine to ensure that any corrupted or outdated packages are not causing the issue. You can find the package cache location in the NuGet configuration settings or manually delete the contents of the
%LocalAppData%\NuGet\Cachefolder.Update NuGet: Ensure that you are using the latest version of NuGet. Update NuGet to the latest version using the Visual Studio Extensions and Updates manager or by running the following command in the NuGet Package Manager Console:
Update-Package NuGet.Retry package restoration: Sometimes, the error can occur due to a temporary network glitch. Retry the package restoration process after some time to see if the issue resolves itself.
If the issue persists after trying these steps, you may need to provide more details about your specific environment and configuration for further assistance.