If you ever see one of the following error messages when you try to run ZEMAX then there is either an installation error, or a hardware problem with either the key or the computer.
 

This is a hardware key error, the key must be returned for replacement. No troubleshooting is possible.

The key is an obsolete, no longer supported type. The key must be returned for replacement. No troubleshooting is possible.

This may be software or hardware related, see below.

Make sure your key is plugged in!

The 'Key security failed' error , and 'Key is obsolete' error, are  fatal errors. No troubleshooting is possible. The key has failed, or is no longer supported, and must be returned for replacement. The replacement key will be a USB key. See this article for return instructions.

If you are getting the 'cannot find ZEMAX key, the driver may not be installed' error, there is either a driver installation error, or a hardware problem with either the key or the computer. We first assume that the problem is not hardware related, and that the key driver installation is faulty or corrupt in some way. Follow these steps:

1. Log onto the machine with a user account with Administrator privileges.
2. Remove your hardware key from the computer, and also remove the hardware keys of any other software that uses hardware key license activation.
3. Visit the downloads page, and download and run the key driver cleanup utility for your version of Windows. This will remove the existing key driver, and will require a reboot of the machine.
4. Visit the downloads page, and download and run Sentinel Protection Installer. It is essential that you use the version on the downloads page, and not any previous version.
5. When the installer completes, plug in your key, and run ZEMAX again.

If you continue to get the 'Cannot find ZEMAX key' after uninstalling and reinstalling the latest version of the driver, then either there is a hardware fault with the key, or with your computer's hardware.

The easy way to identify where the problem lies is to install ZEMAX and the key driver on a second machine. If the key cannot be found on either machine, the key is faulty and should be returned for replacement.

If ZEMAX finds the key on the second machine but not the first, there is a machine-specific issue. ZEMAX support cannot help diagnose hardware problems on your computer.

Although ZEMAX support cannot help you diagnose hardware problems on your computer, here is a list of issues we have encountered before that may be helpful:

• Power management software may turn the power to USB or parallel ports off. Power management software usually defines a computer as being 'in use' when the keyboard and mouse are being used. During long calculations, power management software sometimes concludes that the computer is not in use, and so shuts down power to the USB and parallel ports, makes the processor run at a slower clock speed, turns off power to the hard drives etc. All these can cause unexpected problems when running any computationally intensive application. We recommend power management software be either correctly configured or turned off.
• Your computer's BIOS may have USB and/or parallel port operation turned off.
• Over-zealous systems administrators may lock computers down so tightly that they are useless. ZEMAX must be allowed to access the USB ports, and have read/write and modify privileges for its own folders and any others it is required to read and write data to.