Add JetBrains diagnostics to Copilot troubleshooting (#45208)

Co-authored-by: hubwriter <hubwriter@github.com>

Author: devm33

content/copilot/troubleshooting-github-copilot/viewing-logs-for-github-copilot-in-your-environment.md

@@ -64,6 +64,28 @@ If you find the log file doesn't contain enough information to resolve an issue,
 1. Keep using your IDE until you encounter the issue again, then collect the log file as described in "[Collecting log files](#collecting-log-files)."
 1. When you have the information you need, disable debug mode by removing `#com.github.copilot:trace` from the "Custom Debug Log Configuration" window.
 
+## Viewing network connectivity diagnostics logs
+
+If you encounter problems connecting to {% data variables.product.prodname_copilot%} due to network restrictions, firewalls, or your proxy setup, use the following troubleshooting steps.
+
+1. In the menu bar, click **Tools**, select **{% data variables.product.prodname_copilot%}**, and click **Log Diagnostics**.
+1. The `idea.log` file should open in the JetBrains IDE with the diagnostics output. Alternatively, you can open the `idea.log` file in your preferred editor.
+1. Check the section on **Reachability** to determine if {% data variables.product.prodname_copilot%} can access the necessary services.
+
+## Troubleshooting certificate-related errors
+
+{% note %}
+
+**Note:** If your error is related to certificates, it helps to check these logs for the `Custom Certificates:` line. If this line says `disabled`, you are not using {% data variables.product.prodname_copilot_for_business %}, so custom certificates are not supported. For more information, see "[AUTOTITLE](/copilot/overview-of-github-copilot/about-github-copilot-for-business)."
+
+{% endnote %}
+
+If you're using a custom certificate, ensure the certificate is installed correctly in the operating system, see "[AUTOTITLE](/copilot/troubleshooting-github-copilot/troubleshooting-network-errors-for-github-copilot)". Then use the following troubleshooting steps.
+
+1. In the menu bar, click **Tools**, select **{% data variables.product.prodname_copilot%}**, and click **Log CA Certificates**.
+1. The `idea.log` file should open in the JetBrains IDE with the trusted CA certificates logged in PEM format. You may need to refresh the `idea.log` file to view all of the output. Alternatively, you can open the `idea.log` file in your preferred editor.
+1. Check to see if the expected custom certificate is included in the certificate list output.
+
 {% endjetbrains %}
 
 {% visualstudio %}