Occasionally your Mac will ask if Google Chrome should be allowed to 'find devices on local networks'. In order for Vivi to work on Google Chrome, you must click allow.
Another way you can check if this permission has been allowed is via the following steps:
Open 'System Settings' on your Mac
Look for and select the 'Privacy & Security' menu
In the list of permissions, look for 'Local Network'
Make sure that 'Google Chrome.app' is switched on.