The access control list is full. If you need to add new users, place existing users into groups on the list.

What happened

The database access control list (ACL) for the selected database doesn't have room for additional names.

What you can do

To add names, click File > Application > Access Control, examine the current names in the list and move as many as possible into user groups (add the new names and groups to the HCL Domino® Directory). Delete the moved names from the list and add the new ones. If possible, also add the new names to groups.

Note: In previous versions of HCL Notes®, applications were called databases. A Notes application can consist of one or more databases, each of which can have unique ACLs.