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