If you have attempted to install in5 and received this error message: "Not authorized to send Apple events to System Events"...

Here is a possible solution: 

1. Select System Preferences (from the Apple Menu)

2. Click Security & Privacy

3. Select the Privacy Tab

4. Select Automation (you may need to scroll down)

5. Select the checkbox next to the "System Events.app" for the in5 - Mac Installer.app

In our internal testing, this solved the issue in February 2021 on a MacBook Pro running MacOS Catalina Version 10.15.7.