You discover that the Microsoft Exchange Server offline address book (OAB) has skipped some items and that event 9414 is logged in the Application log. This logged event resembles the following:
Event ID: 9414
Description: One or more properties cannot be read from Active Directory for one or more properties cannot be read from Active Directory for recipient '/o=Contoso/ou=Administrative Group/cn=Recipients/cn=User 1' in offline address book for '\Offline Address List - Contoso'.
When Exchange Server detects a bad object such as User 1, as shown in the example in the "Symptoms" section, the OAB generation process frequently skips several good objects (in addition to the bad object). This behavior occurs because of the way the process handles bookmarks.
To fix this issue, check the Application log for event ID 9414, and then fix all the indicated objects. Or, you can use the OABValidate tool to find the objects that have problems.
Note Event 9414 is an option in Exchange 2010 SP2 RU6 and later.