There is an acknowledged bug in the latest update to Mac InDesign CC, 14.0.2. You are most likely to run into it if you are trying to register your License Key, using the Register button in IDImposer. The registration dialog will display, but then both IDImposer and InDesign will lock up when you attempt to dismiss the Registration dialog, requiring you kill InDesign (Command-Option-Esc).
This is obviously a major issue, and affects many scripts, not just IDImposer.
The only known workaround is to back out of the 14.0.2 update, and run 14.0.1, or earlier release of InDesign CC, or InDesign CS6.
If you want to learn more about the issue, see this Adobe forum discussion: https://forums.adobe.com/message/11071586#11071586