This issue exists in when you create and run a script UI in InDesign or InCopy to open a dialog box, which further opens another dialog box. Now, when you close the second dialog box, InDesign or Incopy becomes unresponsive and you need to restart the application.
This issue exists with InDesign and InCopy 14.0.2 on the macOS platform.
Before you perform the resolution steps, ensure that you have InDesign or InCopy 14.0.2 installed on your system. You can check the version installed on your system by going to Help > About <application name>.
You can update the version on your system from the Creative Cloud desktop app. For more information, see Update Creative Cloud apps.
Download the CopyPlugin.zip to resolve the issue for macOS.
To install and run the plugin, follow the same steps as listed above for InDesign. Ensure that you select the Adobe InCopy 2019 application on macOS.