Iguana install comes with Chameleon application. In certain scenario, you might need to install particular version of Chameleon. See below for detail:
Common Scenarios for manually Install Chameleon
Dedicate Windows for Chameleon app only: use this Windows for editing VMD… not for Iguana Interfaces
Particular version of Iguana that has Chameleon problem. (Error)
How to
Create an install directory.
Download the latest Chameleon no-installer file from our download site:
Extract the contents of this file, and move them into the folder into which you want to install the additional copy of Chameleon.
To start this copy of Chameleon, double-click VMstudio.exe in the install directory.
Follow the Register Chameleon steps – from the “Using the Windows installer” section above.
Reference
For more detail: https://help.interfaceware.com/v6/how-to-install-chameleon