There are 3 reasons why you cannot see a croudies capacity: 

The delivery date is not set on a task -  If you are ever missing capacity on a Croudie you expect to see it on this is likely to be the culprit. The delivery date is needed to work out capacity as it calculates using the work a croudie has assigned to them between the start date and delivery date. 

The Croudie has not set their expected work hours -

Capacity is worked out by taking a Croudies expected hours and comparing it against hours assigned to them. We cannot do this without knowing a Croudies expected hours so this means there is no capacity for these croudies missing the information. 

The Croudie has set themselves as unavailable between the start date and delivery date -

This changes a Croudies capacity and we cannot estimate if they would be high/medium or low based on this information. This makes the capacity of these Croudies is unknown.