License

The License tab allows you to activate and manage your LinFIR license.

License Features

A valid LinFIR license unlocks advanced analysis features:

• Off-axis measurements: Import and analyze measurements at angles other than 0° (horizontal and vertical)
• Directivity Index (DI): Calculate and visualize directivity patterns across frequency
• Directivity Sonogram: Access the Directivity Sonogram window for detailed visualization
• Multi-angle visualization: View multiple measurement angles simultaneously in graphs
• Harmonic distortion details: View individual harmonic levels (THD breakdown by harmonic)
• Hypex FusionAmp mode: Create projects for Hypex FA series amplifiers with hardware-locked parameters and HFD export

Without a license, LinFIR operates with full functionality for on-axis measurements only (0°, 0°). The following features are unavailable without a license: off-axis analysis, directivity tools (DI and sonogram), harmonic distortion breakdown by harmonic, and Hypex FusionAmp project creation.

Activating Your License

If you don’t have an active license, the License tab will display an activation form.

Activation Process

1. Enter your license key

   • Format: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
   • Provided in your purchase confirmation email

2. Enter your email address

   • Must match the email used for purchase
   • Used for license validation

3. Click “Activate License”

   • Creates a new activation tied to this specific machine
   • Each activation is identified by a unique instance name and ID

Important:

• Each license allows one activation at a time
• Each activation is machine-specific
• You must deactivate one machine before activating another
• You can manage activations from the License tab

License Status

When a license is active, the License tab displays:

Current License Information

• Customer name: License holder’s name
• Email: Email address associated with the license
• Product: LinFIR license type
• Status: Current license status (active, expired, etc.)
• Activations: Number of active machines (e.g., “1 / 1”)
• Last checked: Date and time of last validation

This Machine

• Instance Name: Automatically generated name for this activation
• Instance ID: Unique identifier for this machine’s activation

Managing License Activations

Validate License

Click “Validate License” to check the current status of your license with the licensing server.

Use cases:

• Verify license is still active
• Update activation count
• Check for license changes

Deactivate This Machine

Click “Deactivate This Machine” to free up this activation slot.

When to use:

• Switching to a different computer
• Freeing up an activation for another machine
• System reinstall or hardware change

Effect:

• Removes this machine’s activation
• Frees one activation slot
• License features will no longer be available on this machine
• You can reactivate on this or another machine later

Managing Other Activations

The “All License Activations” section displays all machines where the license is currently active.

For each activation:

• Name: Instance name
• Instance ID: Unique identifier
• Created: Activation date

Actions:

• This Machine: Marked with ✓ (cannot be deactivated from this view)
• Other machines: Click “Deactivate” to remove that activation remotely

Use case: If you activated LinFIR on a machine you no longer have access to, you can deactivate it from here to free up that slot.

Troubleshooting

Unable to reach the license server

Symptoms: Activation fails with a message about a network proxy, firewall, or “temporarily unavailable”.

Causes: The license server is protected by Cloudflare. A corporate firewall, VPN, proxy, or content filter may intercept the request and return an HTML page instead of a valid response.

Solutions:

1. Disable VPN or proxy temporarily and try again
2. Check firewall rules: ensure outgoing HTTPS connections to api.lemonsqueezy.com are not blocked
3. Try a different network: switch to a mobile hotspot or home network to rule out corporate filtering
4. Wait and retry: Cloudflare rate limiting is temporary — try again after a few minutes
5. Check your internet connection: ensure basic web browsing works before activating

“No Active License” but I activated

Symptoms: The License tab shows no active license despite a previous activation.

Solutions:

• Click “Validate License” to refresh status from the server
• Check internet connection
• The activation may have been lost (e.g., after a system reinstall) — activate again using your license key and purchase email

Too many activation attempts (rate limited)

Symptoms: Activation fails with a message about too many requests or rate limiting.

Solution: Wait a few minutes and try again. Repeated failed attempts (e.g., due to a network issue) can temporarily trigger rate limiting on the server.

Activation limit reached

Symptoms: Activation fails with “Activation limit reached”.

Cause: Your license is already activated on the maximum number of machines allowed.

Solutions:

1. Scroll down to the “All License Activations” section in the License tab
2. Identify machines you no longer use and click “Deactivate” next to them
3. Then try activating this machine again
4. If you no longer have access to the machine listed, use “Deactivate” to free up that slot remotely
5. Contact support if you need additional activation slots

Wrong email or license key

Symptoms: Activation fails with an error about an invalid key or email mismatch.

Solutions:

• Use the exact email address from your purchase confirmation (check for typos, extra spaces)
• Copy and paste the license key directly from the confirmation email to avoid transcription errors
• If you cannot find your purchase email, contact support

License deactivated on this machine

Symptoms: A toast appears saying “License has been deactivated for this machine”.

Cause: The license was revoked, expired, or deactivated remotely (e.g., from another device).

Solutions:

• Click “Validate License” to confirm the current status
• If the license is still valid, re-enter your license key and email to reactivate

License not validating

Symptoms: Background validation silently fails (no toast) or shows a warning about license status.

Solutions:

• Ensure internet connection is active
• Check firewall settings (HTTPS access to api.lemonsqueezy.com required)
• Verify your license has not expired by checking the status in the License tab
• Click “Validate License” to trigger a manual check

Privacy & Data

What is stored:

• License key (encrypted)
• Email address
• Instance name and ID (machine identifier)
• Activation timestamps

What is sent to licensing server:

• License key
• Email address
• Instance information (for activation/validation)

No project data, measurements, or filter designs are transmitted during license operations.