I can't add a contact to an event
If you can’t add a contact to an event, it could be for one of these 3 reasons:
The event has a fixed capacity for guests and has reached its limit
The contact is not in the Enrolled state of the project that owns the event
The contact has not been added to the project that owns the event
How to fix the problem
If the event has a fixed capacity for guests and has reached its limit
You can
either increase the capacity of the event (You need to be an Event Manager or Project Manager to do this)
or remove a guest from the event to make space for your new contact
If the contact is not in the Enrolled state of the project that owns the event
Watch this 1min30second explanation video:
You simply need to toggle the Filter to include Waiting List (and indeed any other states) as well as Enrolled
The contact has not been added to the project that owns the event
You can
either add the contact to the project that owns the event. (How to add a contact to a project)
or turn on the option that lets you add contact who is outside a project to an event owned by that project (How to turn that on and How to use it)