Online license verification failed: UNKNOWN_HOST

Symptoms

When the license key is applied to the TeamCity server, an error is displayed: "Online license verification failed: UNKNOWN_HOST (Could not resolve the host account.jetbrains.com. Check your network settings)."

Cause

The TeamCity server is unable to resolve or connect to account.jetbrains.com. This could be due to DNS resolution issues, network connectivity restrictions, or the server running in an isolated network environment, such as behind a firewall or proxy.

Resolution

1. Verify that the machine where the TeamCity server is running can resolve and access account.jetbrains.com. Test this with the following commands from the server:

   nslookup account.jetbrains.com
   curl https://account.jetbrains.com
   

2. If the server is running in an offline or restricted network environment, this warning is expected. However, note that:

   • The license has been successfully applied and is functional.
   • Online license verification and automatic license updates will not be available until the server can reach account.jetbrains.com.

3. For more information, refer to the documentation on Offline Mode.

Since the issue does not prevent normal use of TeamCity, no immediate action is required beyond investigating the network connectivity if needed.