Exchange OWA Unable to Access Some Calendar Items - Outlook Works OK
Posted on 2012-03-18
I have an interesting seemingly widespread problem with OWA on Exchange 2003. I have users reporting that some calendar items that were entered using Outlook are not syncing with their mobile device.
While troubleshooting I found that accessing their mailbox from OWA I was able to see the missing calendar item on the calendar but was unable to open it. Attempting to open it reports HTTP 500 Internal Server Error - The website cannot display the page. However, I CAN open the same item in Outlook.
There are many items in the calendar and only a few are not accessible from OWA. I am unable to recreate the problem. The person that enters the calendar items insists that all calendar items are created using the exact same process and all are basically the same structure, i.e. the format of the subject line is basically the same with the same special characters present in all calendar items. I thought at first the subject line in the offending items was too long and contained unusual special characters such as : and / or \ but many with the same structure work fine.
I did a side-by-side comparison of the URLS from one good and one bad calendar item and nothing seems to be obviously wrong.
I have opened the bad calendar items with mdbvu32 to see if there was something strange but so far I have only noticed that mdbvu32 crashes a lot. I did receive the following message when using mdbvu32:
The permission on Mapi_folder - Calendar are incorrectly ordered which may cause some entries to be ineffective. Press OK to continue and sort the permissions correctly or cancel to reset the permissions.
Choosing OK shows the delegate permissions on the folder. Clicking OK on the permissions dialogue reports a message about Deny permissions being assigned and they will override other access permissions, just normal ACL stuff.
Another error I received when opening the calendar item properties was:
CPropDlg::RedrawPropTable() IpEntry->GetProps(): MAPI_W_ERRORS_RETURNED
The only problem is, I received this error when opening bad calendar items AND when opening GOOD calendar items. So I think these messages may be misleading even though I'm not sure what the errors mean.
My environment is as follows:
Windows Server 2003 SP2
Exchange 2003 SP2
OWA with Forms Authentication Enabled
Testing was performed using IE8 from a domain PC on internal network. Accessing OWA externally exhibits the same errors.
I'm at a loss. Can anyone offer another approach to the problem that I haven't thought of?