couple days ago started seeing numerous 8263 errors on our CCR mailbox role servers. Currently all running 2007 SP1. How does one troubleshoot these Warnings? Any insight in to what might be causing it? We have ruled out any backup or antivirus issues. Thanks for any help. =====================================================================Event Type:WarningEvent Source:EXCDOEvent Category:General Event ID:8263Date:6/1/2009Time:10:42:49 AMUser:N/AComputer:MAIL-MBX02Description:The recurring appointment expansion in mailbox <mailbox name> has taken too long. Some recurring appointment instances may not be visible at this time. For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.=====================================================================

Just as a followup to my own post the increased frequency started occurring Friday am after I failed over the cluster to install windows updates. Typically I fail it back after reboot but didnt this time. I just failed it back to the typical primary node and the warnings have stopped. Both CCR nodes are identical setup softare/hardware, etc... Any ideas/insight? Thanks for your help

Hi, I would like to explain that this Warning event indicates that an e-mail client that accesses calendar data using Microsoft Office Outlook Web Access was unable to successfully display all calendar items for a specific calendar view. This error may occur if a user has many calendar items that meet the criteria of the specific calendar view. For your reference: http://www.microsoft.com/technet/support/ee/transform.aspx?ProdName=Exchange&ProdVer=6.5.7596.0&EvtID=8263&EvtSrc=EXCDO&LCID=1033 Mike

thank Mike, but are users do not use OWA and Im intrigued by the fact that the issue presents itself depending on which is the active node in the CCR cluster. Could be that I require a reseed.thanks

Hi, Please let me know whether the mailbox user indicated in the event report any problems when opening their Calendar folder. If not, I would like to explain that we do not to reseed the database. In addition, based on my research, the issue mostly occurs that some recurrence calendar items have invalid end date. Therefore, if the event occurs again, I also suggest you open the user mailbox indicated in event by using Outlook: 1. Click Calendar Folder 2. Click View, Current View, Recurring Appointments 3. Please check whether any Recurring Appointments have invalid end time by checking Recurrence Range End Column. Mike