Academic License Troubleshooting#

This guide covers some common issues when activating or using Academic licenses, Course Bundle licenses, and other trial licenses such as Community Edition for industry practitioners.

General Licensing Notes#

  • To activate your license in Python, run:

    python -m amplpy.modules activate <license-uuid>

  • Or, in a Jupyter notebook:

    from amplpy import AMPL, ampl_notebook
ampl = ampl_notebook(
    modules=["gurobi", "xpress", "highs"],  # modules to install
    license_uuid=<license-uuid>             # license to use
)

  • Academic licenses require an active internet connection to periodically renew its short-term lease.

  • Install AMPL in your user home directory, typically (on Windows):

    C:\Users\<YOUR_USERNAME>\AMPL\

  • Do not install Academic licenses in read-only locations (e.g., C:\Program Files\AMPL\).

Common Issues & Fixes#

1. License Renewal Error#

Example error:

Please make sure your internet connection is working in order to renew the license
C:\Users\USER\AMPL\ampl.lic: Short term lease expired.

Explanation:

  • The short-term license lease couldn’t be renewed due to:

    • No active internet connection, or

    • Installation in a read-only directory that prevents license updates. This is a typical Windows issue when AMPL is installed in C:\Program Files\AMPL\.

Fix:

  1. Ensure you have a stable internet connection.

  2. Restart AMPL.

  3. If AMPL is installed in a protected directory (e.g., C:\Program Files\AMPL\), reinstall it under:

    C:\Users\<YOUR_USERNAME>\AMPL\

2. “Bundle Expired” Message#

Example error:

# Bundle #2837.7303 expiring 20250215
No ampl license for this machine.

Explanation:

  • Your AMPL bundle license has expired.

Fix:

  1. Log in to your account on portal.ampl.com to check active bundles.

  2. If none are active, request a new one:

  3. If you already had one:

  4. Activate your new license bundle following the installation instructions.

3. Showing demo license after full license activation#

Example symptoms:

  • License activation appears to succeed (no errors) using a command such as:

    ampl: shell "amplkey activate --uuid <license-uuid>";

  • However, when running a model, AMPL still displays a demo limitation message:

    Sorry, a demo license is limited to 2000 variables and 2000 constraints and objectives for linear problems.
You have <N> variables and <M> constraints.

Explanation:

The most common cause is that AMPL was activated in one installation, but the user later runs AMPL from a different installation or executable.

This can happen when:

  • Multiple AMPL installations exist on the system (e.g., in different folders or environments, Amplpy and a previous AMPL-standalone version).

  • The activation was performed using one method (e.g., inside AMPL or via amplkey), but AMPL is later invoked from a different location, like from Amplpy. The other way around is true, activating with `` won’t ensure that an independent previous installation will find the license.

Fix / Diagnostic Steps:

  1. When using Python, you don’t need to run the amplkey command. Ensure activation is done in the same environment and installation:

    python -m amplpy.modules install base --upgrade # update ampl version
python -m amplpy.modules activate <license-uuid>

  2. For standalone installations of AMPL, identify which AMPL executable is being used when running the model. For example:

    which ampl

    or on Windows:

    where ampl

  • Confirm that this is the same AMPL installation where the license was activated, or activate it again:

    ampl: shell "amplkey activate --uuid <license-uuid>";

Reference:

Installation and activation workflow details: https://dev.ampl.com/ampl/install.html

4. “No AMPL License for This Machine” in Synced Folders (e.g., OneDrive)#

Example error:

No ampl license for this machine.
AMPL path:
C:\Users\user\OneDrive - <University>\ampl_mswin64\ampl.exe

Explanation:

  • AMPL was installed in a OneDrive-synced folder.

  • OneDrive may overwrite or lock the license file during synchronization.

Fix:

  1. Move your AMPL installation to a non-synced local directory, such as:

    C:\Users\<YOUR_USERNAME>\AMPL\

  2. Activate your new license using the uuid following the installation instructions.

Extending Solver Trials#

If your trial license for commercial solvers (e.g., Gurobi, CPLEX) has expired, you can request an extension through the AMPL Portal:

AMPL will review your request and grant an extension where eligible.

Contact Support#

If your issue remains unresolved, please include the following when contacting support:

  • The full error message

  • The log file (if available, find it with ampl: shell "amplkey show log";):

    C:\Users\<YOUR_USERNAME>\AMPL\amplkey.log

  • Send it to licensing@ampl.com.