We set up external meetings via CRM by adding related contacts to the event. When in the event you can search for via those contacts you want to invite via related contacts and identify the correct contact by clicking on the button on the left of the contact. By clicking on that button, the contact is added (or should be) added to the event. I have reported this issue twice on the chat and it remains unresolved. Can someone explain how you set up an event and add a contact to that event if the select button doesn't work. If you want me to demo the issue I'm happy to do it for the third time!