Overview
If your V-Ray for SketchUp is showing an "A JavaScript error occurred in the main process" error you will need to check the below solution.
Example
Solution
On your macOS please go to System Preferences > Security & Privacy > Privacy > File and Folders then find SketchUp and make sure that Documents Folder permissions are allowed as shown below:
Important
Please note that you might have more than one SketchUp available there if you have multiple versions installed, please make sure the correct one is selected.