Currently I'm having problem opening another mailbox from Administrator account, it displayed a fatal error page. I've succeed before, but when I tried it again, it showed a fatal error. How to fix this problem?

Are you sure that admin still have Full Mailbox Rights?Regards, Konrad Sagala, MCT, MCSE+M, MCITP: Exchange 2007/2010, Lync 2010, Office365, Windows 2008, Virtualization

I haven't changed the permission system, but how to check that one?

Check by running ExBpa and diagnostic logging

Hi You can run "Get-MailboxPermission" cmdlet on exchange management console. Get-MailboxPermission: http://technet.microsoft.com/en-us/library/aa998218(v=exchg.141).aspxWendy Liu TechNet Community Support

Are you sure that admin still have Full Mailbox Rights? Regards, Konrad Sagala, MCT, MCSE+M, MCITP: Exchange 2007/2010, Lync 2010, Office365, Windows 2008, Virtualization Currently, I'm having role as Organization Management. Does it not enough to open another mailboxes? I've done it before, but somehow these days, I'm failed to open them.