Does anyone know how to solve this problem.

Hello, Exchange 2007? Did you encounter this event ID when moving mailboxes or adding permissions, such as full access permission, to specific mailbox? If the issue occur when adding permission, it should be a known issue and you can apply the latest update to fix this issue. Thanks, Simon

Hi Simon, Thank you for your reply. It is Exchange 2010. This issue occur when adding permission to a shared mailbox. Adding permission (full access permission to specific mailbox) for about 800 users to a shared mailbox is this no issue. So i dont think that this is a known issue. Thanks rebly

Cannot set the security descriptor of mailbox 'bc9cddk2-4df7-482c-a6b5-72451da2ka57' in Exchange mailbox database 'df6c7a64-82ea-486c-b9bk-5830e69d79b1'. + CategoryInfo : WriteError: (0:Int32) [Add-MailboxPermission], MapiOperationException + FullyQualifiedErrorId : FD36837B, Microsoft.Exchange.Management.Recipient Task.AddMailboxPermission

1. First see if security inheretance is checked. Open ADUC, go to the properties of the user account, security tab, advanced button. Is inheretenced checked? If not check it and try again. If that doesnt work 2. open exchange powershell and run set-mailbox user1 -applymandatoryproperties If that doesnt work 3. Open adsiedit, expand domain, keep expanding to the ou where the user is. Right click the user, properties. Find the mailnickname, write that down. Then clear that value and click ok. Then add that value back in. James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com