All Categories FAQ - Troubleshooting Cannot Contact License Server

Cannot Contact License Server

By Volkan Ozyilmaz
January 27, 2021

When an end-user encounters a "Cannot contact license server" error, it typically means the application is unable to establish a secure connection with Keyzy's API to validate the license. This is often due to local network restrictions, security software, or system configurations.

Please follow the steps below to troubleshoot the issue with your customer.

Standard Troubleshooting

Before diving into logs, please verify the following common causes:

  1. Internet Connectivity: Ensure the device has an active and stable internet connection.

  2. Firewall & Antivirus Allowlisting: Security software (Windows Defender, 3rd party Antivirus, or Firewalls) may mistakenly block the connection. Ensure that the software has permission to make outbound connections or that api.keyzy.io is whitelisted on port 443.

  3. Corporate Network Restrictions: If the user is on a corporate or restricted network (e.g., office, university, or VPN), the network administrator may need to explicitly allow access to the keyzy.io domain.

  4. Hardware ID Consistency: Confirm that the user is not running MAC address spoofing software. Keyzy relies on hardware identifiers, and spoofing tools can disrupt the validation process.

Advanced Troubleshooting: Diagnosing Network Issues

If the issue persists, you may need to investigate the specific network response to pinpoint the failure (e.g., DNS resolution failure, SSL handshake blocking, or firewall termination).

To do this, ask your customer to run the following diagnostic command. This will output a verbose log of the connection attempt to the Keyzy API.

You can send the following instructions to your customer:

For macOS and Linux Users

  1. Open the Terminal app (Press Command + Space, type Terminal, and hit Enter).

  2. Copy and paste the following command into the window and press Enter:

    Bash

    curl -v https://api.keyzy.io/v2/status-check
  3. Copy the entire text output displayed in the Terminal and send it to the support team.

For Windows Users

  1. Press the Windows Key, type cmd, and select Command Prompt (do not use PowerShell).

  2. Copy and paste the following command into the black window and press Enter:

    DOS

    curl -v https://api.keyzy.io/v2/status-check
  3. Take a screenshot of the result or copy the text and send it to the support team.


How to Analyze the Output

Once you receive the output from your customer, look for the following clues to identify the root cause:

  • Trying 127.0.0.1... or Trying ::1...:

    • Diagnosis: This indicates that api.keyzy.io is being redirected to the local machine (localhost) instead of Keyzy's actual servers. This is almost always caused by an entry in the user's hosts file.

    • Solution: Ask the user to check their hosts file (/etc/hosts on macOS/Linux or C:\Windows\System32\drivers\etc\hosts on Windows) and remove any lines referencing keyzy.io.

  • Could not resolve host:

    • Diagnosis: This indicates a DNS issue. The user's computer cannot translate the domain name into an IP address.

    • Solution: The user may need to check their internet connection or try changing their DNS settings (e.g., to Google DNS 8.8.8.8).

  • Connect to ... timed out:

    • Diagnosis: This usually indicates that a Firewall or Proxy is strictly blocking the outgoing connection to the server.

    • Solution: The user needs to whitelist api.keyzy.io or allow HTTPS traffic on port 443 in their security software.

  • SSL certificate problem:

    • Diagnosis: The user might be behind a corporate proxy or antivirus software that performs SSL inspection (Man-in-the-Middle) which isn't trusted by their OS.

  • HTTP/1.1 200 OK:

    • Diagnosis: If you see this, the network connection to Keyzy is healthy. The issue likely lies within the application integration or local configuration rather than the network.

Was this article helpful?

Thanks for your feedback!