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16 hours ago

Licensing ‘Know-How’ Guide

Introduction
Sections
Conclusion
Additional

#sharing #debug #altera #alldevices #license

Disclaimer: This article is provided as-is for educational purposes only, without warranty of any kind. Use the information at your own risk. Always verify implementations in your specific environment and consult official Altera documentation for production deployments.

Introduction

Licensing issues are one of the most common reasons FPGA tools fail to start. The good news is that most problems are configuration related and can be fixed quickly by following a simple, step-by-step approach.

Sections

1: Start with the Error Message (Most Important!)

Always look at the first licensing error message shown by the tool. This is usually the real issue. Any errors that appear later are usually caused by the first problem.

Here’s are common error messages and what they usually mean:

Invalid hostid → License does not match your machine ID

Cannot find license file → Invalid or missing license path

Unable to checkout a license → License not found, in use, or server issue

300: License version is outside the range of the contract → license file generated with blank

FLEXlm error: Vendor daemon version is too old → daemon used mismatch or too old

Cannot checkout uncounted license in Windows Terminal Services → Questa does not support remote desktop.

Most common errors already have known fixes. Try searching the error message or key issue at:

Altera Knowledge Base:
https://community.altera.com/category/top/kb/knowledge-base

Altera Community Forums:
https://community.altera.com/category/forums

For floating licenses, you can also check the FlexNet error code list:
Error Code Descriptions

Don’t try to fix everything at once. Fix the first error, then retry. In many cases, the rest will disappear automatically.

2: Check Your License (.dat) File

Open the .dat license file using a text editor (for example, Notepad) and verify the following.

i. Machine ID (NIC / HOST ID)

The license is locked to a specific machine ID.
Example in the license file:
# Primary Machine ID-NIC ID 12AB34C56EF7

If the Host ID doesn’t match your machine ID, the license will not work.

Helpful Tips 1:
----------------------------------------------------- START -----------------------------------------------------

Quartus software can automatically detect the Machine ID. To view this, go to Tools → License Setup, then check Local System Information and select one of the detected NIC IDs.

------------------------------------------------------ END ------------------------------------------------------

ii. License Type
Licenses are set up differently, so confirm which type you have.Look for one of these lines:

# Fixed Node License → Nodelocked license
# Floating Server License → Floating license

Nodelocked: Locked to one machine
Floating: Served from a license server and shared

Make sure you’re following the setup steps that match your license type.

iii. Product License Summary
Find the Product License Summary section and confirm it lists the tools/IP you’re planning to use. Examples:

Quartus® Prime Software (Standard / Pro)
Questa® FPGA Starter Edition (SWQUESTA)

If a tool or IP is not listed here, it won’t be able to check out a license—even if the license file setup successfully.

iv. License Expiration & Maintenance
Licenses can look similar but behave very differently. We have:

a. Perpetual License

Has a Maintenance Expiration date
You can use tool versions released before that date

Example shown in license file:
# Maintenance Expiration of 2026.06
# No license expiration date

b. NonPerpetualLicense

Has a hard expiration date
License stops working after this date

Example shown in license file:
# License Expires 20Jun2026

Always doublecheck the license expiration & maintenance date before moving on.

3. Verify Environment Variables

The tools use environment variables to find the license. If these are wrong, the tools may not find your license—or may use an old license file.

Common environment variables:
Different tools use different environment variables to locate the license.

LM_LICENSE_FILE → Quartus® Prime
SALT_LICENSE_SERVER → Questa* FPGA Edition

Depending on the license type, they should point to:

Nodelocked license: Full path to the .dat file
Floating license: port@hostname

Examples:
LM_LICENSE_FILE=C:\licenses\license.dat
LM_LICENSE_FILE=25000@licenseserver

Next verify the environment variable.
Open Command Prompt and run:

echo %LM_LICENSE_FILE%

If nothing is printed, the environment variable is either not set or the changes have not taken effect. If it is the latter, close and reopen the command prompt after making the changes. If the variable points to an incorrect location, update it accordingly.

Note that outdated or incorrect environment variables are a very common source of issues.

Helpful Tips 2:
----------------------------------------------------- START -----------------------------------------------------

There is a quick way to set using command line. Open Command Prompt and run:

Windows:

setx LM_LICENSE_FILE <path_to_license_file>

Linux:

setenv LM_LICENSE_FILE "<path_to_license_file>"

------------------------------------------------------ END ------------------------------------------------------

4. Check the License Server (Floating Licenses Only)

If you’re using a floating license, verify the server.
On the client machine:

Server hostname resolves correctly
Network is working
Firewall is not blocking the license port

On the license server:

License server process is running
Vendor daemon is running
Server log shows no fatal errors
Licenses are available (not all checked out)

If the server isn’t running properly, clients won’t be able to get licenses.

5. Scenario / Walkthrough

A floating license setup walkthrough (Know-How: Set Up a Floating License) is available to guide you through the complete process of configuring a floating license.

Know-How: Set Up a Floating License (Step-by‑Step Walkthrough) | Altera Community - 352000

Conclusion

Licensing issues are almost always setup or configuration problems.
Following this guide step-by-step starting with the error message will resolve most issues.

If you’re still stuck after trying all the steps, feel free to post your issue on the Altera Community Forum (https://community.altera.com/category/forums) for help. When posting, please try to include the following:
i. Error Details

The exact licensing error message, copied as is
If there are multiple errors, include the first one shown

ii. Tool Information

Product name (example: Quartus/Questa)
Tool version (example: Quartus Pro 25.3/ Questa Altera FPGA Edition 2025.2)
Operating system (Windows or Linux, version if known)

iii. License Information

License type:
Nodelocked (fixed)/ Floating (network)
Purchased / Evaluation license
If possible, a copy of the license file (.dat)

iv. What You’ve Already Tried

Steps you have already checked or attempted
Any workaround that partially worked

The more complete your post, the faster the community (and Altera support staff) can help.

Additional

Altera Support Webpages

For further information related to licensing, you may check out Altera Licensing Webpages for the wholesome experiences to get your FPGA licensing product setup and running with minimal hassle: