VSTS Test Agent - IPC Port Access Denied

When encountering an "IPC Port Access Denied" error with VSTS Test Agent, it typically indicates that the Test Agent is unable to establish communication with the VSTS (Azure DevOps) server due to a port access restriction or firewall blocking the communication.

To resolve this issue, you can try the following steps:

1. Check Firewall Settings: Ensure that the firewall on the machine running the Test Agent allows outbound communication on the required ports. By default, the Test Agent uses ports 80 and 443 for communication with the VSTS server. Make sure these ports are open and not blocked by the firewall.

2. Verify Proxy Configuration: If your organization uses a proxy server for internet connectivity, ensure that the Test Agent is configured to use the correct proxy settings. You can update the proxy configuration in the Test Agent's config.cmd file located in the agent installation directory.

3. Run Test Agent as Administrator: Try running the Test Agent as an administrator to ensure it has the necessary privileges to establish the IPC communication. Right-click on the Test Agent shortcut or executable and choose "Run as administrator."

4. Check Network Connectivity: Verify that the machine running the Test Agent has a stable network connection and can access the internet without any restrictions. Issues with network connectivity or network configuration can impact the Test Agent's ability to establish communication with the VSTS server.

5. Temporary Disable Antivirus/Firewall: Temporarily disable any antivirus or firewall software on the machine running the Test Agent to check if they are causing the access issue. If disabling the antivirus/firewall resolves the problem, you can then configure them to allow communication on the required ports.

By following these steps, you should be able to troubleshoot and resolve the "IPC Port Access Denied" error with VSTS Test Agent, allowing it to establish communication with the VSTS server.