I have Exchange 2010, running update rollup 3. I know it is not supported but we are running address list segregation - everything else is working, this is the only error we are experiencing. When I open OWA 2010 and go to the address book and try to search I get the error message shown below. I have already tried suggestions from the following to no avail: http://social.technet.microsoft.com/Forums/en-US/exchangesvrdeploy/thread/517d02ea-8aea-45c7-9ca0-3be117440e10?prof=required http://blogs.msdn.com/b/dgoldman/archive/2007/12/05/deleting-the-all-rooms-address-list-stops-it-from-showing-up-in-owa.aspx Error: Request Url: https://mycas:443/owa/ev.owa?oeh=1&ns=DB&ev=LoadFresh User host address: 1.2.3.4 User: User EX Address: /o=Hosting/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=user SMTP Address: user@email.com OWA version: 14.0.694.0 Mailbox server: casserver.local Exception Exception type: System.NullReferenceException Exception message: Object reference not set to an instance of an object. Call stack Microsoft.Exchange.Data.Directory.SystemConfiguration.AddressBookBase.GetScopedRecipientSession(ADObjectId rootId, Int32 lcid, String preferredServerName, AddressBookBase addressBook) Microsoft.Exchange.Data.Directory.SystemConfiguration.AddressBookBase.PagedSearch(ADObjectId rootId, AddressBookBase addressBookBase, RecipientCategory recipientCategory, String searchString, Int32 itemsToSkip, String& cookie, Int32 pageSize, Int32& itemsTouched, Int32& lcid, String& preferredServerName, PropertyDefinition[] properties) Microsoft.Exchange.Clients.Owa.Premium.Controls.ADListViewDataSource.LoadPagedSearch(Int32 startRange, Int32 itemCount, PropertyDefinition[] properties, Boolean retry) Microsoft.Exchange.Clients.Owa.Premium.Controls.ADListViewDataSource.Load(Int32 startRange, Int32 itemCount, Boolean retry) Microsoft.Exchange.Clients.Owa.Premium.Controls.ADListViewDataSource..ctor(Hashtable properties, AddressBookBase addressBookBase, String searchString, String cookie, Int32 cookieIndex, Int32 lcid, String preferredDC, UserContext userContext) Microsoft.Exchange.Clients.Owa.Premium.Controls.ADListViewDataSource.CreateForSearch(Hashtable properties, AddressBookBase addressBookBase, String searchString, UserContext userContext) Microsoft.Exchange.Clients.Owa.Premium.Controls.AddressBookVirtualListView.CreateDataSource(Hashtable properties) Microsoft.Exchange.Clients.Owa.Premium.Controls.VirtualListView2.LoadData(Int32 startRange, Int32 rowCount) Microsoft.Exchange.Clients.Owa.Premium.Controls.AddressBookVirtualListView.LoadData(Int32 startRange, Int32 rowCount) Microsoft.Exchange.Clients.Owa.Premium.VirtualListViewEventHandler2.InternalLoadFresh(Boolean renderHeaders) Microsoft.Exchange.Clients.Owa.Premium.DirectoryVirtualListViewEventHandler.LoadFresh()

As you said, you have GAL segregation. As far as my understanding goes, you must have taken out the permissions for some accounts from ADSIEDIT. Check for proper permissions over there. Can you see the GAL properly in OL. How about OAB, can you see proper GAL once you are offline?Raj

As you said, you have GAL segregation. As far as my understanding goes, you must have taken out the permissions for some accounts from ADSIEDIT. Check for proper permissions over there. Can you see the GAL properly in OL. How about OAB, can you see proper GAL once you are offline? Raj That is correct, authenticated users and Everyone is removed from AL, GAL & OAB permissions. Also, inheritance is taken off. Exchange Trusted Subsystem is also given Full Permissions. Address lists work 100% in Outlook, including Autodiscover and OAB.

Hi, We will *to provide support* for Exchange 2010 address list segregation once white paper for Exchange 2010 addrss list segregation finish. So now, please do not follow the steps for Exchange 2007 to do address list segregation for Exchange 2010. Exchange 2007 and 2010 Address List Segregation changes http://blogs.msdn.com/b/dgoldman/archive/2010/01/06/exchange-2010-address-list-segregation-as-of-now-is-100-unsupported.aspx Regards, Xiu

The solution to this problem is very simple if you carefully read the Microsoft white paper on Exchange 2007 address list segregation. http://technet.microsoft.com/en-us/library/bb936719%28EXCHG.80%29.aspx On the "msExchQueryBasedDN Configuration" topic it states that this value can be "set to the distinguishedname (DN) of the OU or an address list containing the correct group of users." In Exchange 2010, setting the DN value to the OU causes this error. By changing this value to the DN of the address list of the specific segregated group, this error should be fixed. ------------------------- ImadImad