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Support FAQs

How do I uninstall the software?

Open the Help menu and select Registration Information to open the Registration dialog. At the bottom of the dialog, click Deactivate Software. If you use Windows, go to Programs and Features in the Control Panel and use the “Uninstall a program” option to complete the deinstallation. If you use a Mac, drag the software from your Applications folder to the Trash, then empty the Trash.

Why can’t I open a model with an .stm or .itm extension?

Models with .stm or .itm file extensions were built in our older line of software and can’t be opened in Stella Architect or Stella Professional. These models can be converted to the correct file format to be opened in Stella Architect or Stella Professional. You can send these models to and we will convert them for you.

Every time I start the software on my Mac, it prompts me for my registration number. How can I make it stop?

You may have a program that cleans your Mac settings daily. You’ll need to edit its settings to prevent it from cleaning our software.

Can I publish simulations privately?

Yes, isee systems provides several ways to publish simulations privately. Please contact for more information, or see When you publish a simulation to the isee Exchange, is it available to everyone?

Why do I get the message “can’t connect to isee systems license server” when trying to activate my software?

This usually means that your network’s firewall is preventing your computer from sending information to the server that activates your license. In that case, you’ll be prompted to use the Web browser method for installation. (This does not apply to the Lab Pack or Site license.)

How do I renew my support?

If you are notified that your support is about to or already has expired, please send an email to with your registration number(s) and request a quote. Or you can call us at 603-448-4990 and customer service will help you.

When I enter the registration number for a Lab Pack or site license, why do I get the message “Invalid use of a Lab/Site License Registration Number”?

Lab Packs and site licenses require special installation processes, so their registration numbers can’t be entered directly into the software. Their installation instructions can be found under the registration number for that license in your isee account.

What does the Maintenance and Support Contract include and what are its terms?

The contract includes all software updates and allows you to request software installation assistance, troubleshooting and general “how-to” advice over telephone or email.

Why can’t I see my model’s interface with the isee Player?

The isee Player lets you open and run a Stella model. You can use Stella Live to view results. The interface is not available in the isee Player.

Looking for software help?

Phone: (603) 448-4990 Email:

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24 Hanover St, Ste 8A | Lebanon, NH 03766 | US

isee systems inc. holds trademarks registered in the U.S. Patent and Trademark Office for iThink®, Stella®, isee systems® and claims the following trademarks; isee NetSim™, isee Exchange™, Stella Live™, Causal Lens™, Stella Online™, Stella Professional Online™, and Assemblies™.

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