Event ID 27, "Calendar Folder property is missing," after you apply Office 2010 SP2

Applies to: Microsoft Outlook 2010


After you apply Microsoft Office 2010 Service Pack 2 (SP2) or hotfixes released after SP2,  users may see many Event ID 27 warnings from Outlook in the Application log. This issue occurs for users who have a PST attached to their profile. This includes PSTs that were created by connecting to a Microsoft SharePoint site. 

The following is an example event in the Application log:

Log Name: Application
Source: Outlook
Date: 10/1/2013 1:55:04 PM
EventID: 27
Task Category: None
Level: Warning
Keywords: Classic
User: N/A
Computer: client1.corp.wingtiptoys.com
Calendar Folder Property is missing


To resolve this issue, install the Outlook 2010 hotfix package that is dated December 10, 2013. For more information about this hotfix package, click the following article number to view the article in the Microsoft Knowledge Base:
2849973 Description of the Outlook 2010 hotfix package (Outlook-x-none.msp): December 10, 2013


If you are unable to install the Outlook 2010 December 10, 2013 hotfix package, you can use the following workaround. To work around this problem, PSTs can be removed from the profile. To remove PSTs from your Outlook profile, follow these steps:
  1. Open Microsoft Outlook 2010.
  2. Click File, and then click Account Settings.
  3. Click the Data Files tab.
  4. Select the data file that you want to remove, and then click Remove.
Removing PSTs from your profile will not remove the PSTs from your system. Removing some PSTs may result in loss of functionality in Outlook. For example, removing the SharePoint Lists PST will remove connections to SharePoint sites.