Registrations to an event in BBCRM who are marked as will not attend are included in the total event capacity for the event in BBIS.
This issue has been resolved in BBCRM 4.0 SP7 (4.0.158).
Release notes for SP7 can be found here : https://www.blackbaud.com/files/support/downloads/bbec/CRM40SP7ReleaseNotes.html
Steps to Duplicate
1. Create a new event in BBCRM with a capacity of 3 2. On the registrations tab add a new registration. 3. Click on the registrant and select 'mark as' then select will not attend 4. Note over all event capacity should stay at 3 5. Create an event registration form in BBIS ensure that the event is linked to the one you created in step 1 and that Restrict Registrations to capacity is selected. 6. In the pricing options set the max units to 3 7. Test the page and try to add 3 registrants notice warning The quantity specified exceeds the amount we have available for <event name> event.