Summary:
In order to add approved time off requests to an Outlook calendar, Outlook requires that a certain file format translator be installed on the user’s computer. If this file is missing or damaged in some way, users attempting to add a time off request may be prompted to install this translator. This installation should occur automatically once the user responds 'Yes' to the prompt. If installation of the translator does not occur automatically, the user can install the file format translator manually.

Resolution:
To manually install the Outlook file format translator:

  • Exit out of Outlook.
  • Remove the Msocache folder. (For more information about how to remove the Msocache folder, refer to Microsoft Support, Knowledge Base 825933 at support.microsoft.com/kb/825933/.)
  • Click Start, and then click Control Panel.
  • Click Add or Remove Programs.
  • In the Currently installed programs list, click Microsoft Office 2003, and then click Change.
  • In the Microsoft Office 2003 Setup dialog box, click Add or Remove Features under the 'Maintenance Mode Options' area, and then click Next.
  • Under the 'Custom Setup' area, click to select the Choose advanced customization of applications check box, and then click Next.
  • Under the 'Choose update options' for applications and tools area, expand Microsoft Office Outlook.
  • Click the down arrow next to Importers and Exporters, and then click either the Run from 'My Computer' option or the 'Run' all from My Computer option.
  • In the Microsoft Office 2003 Setup dialog box, click Update.

Note:
Before making any changes to Outlook always backup your PST file. 
For more information on this procedure, refer to Microsoft Support, Knowledge Base 829985 at support.microsoft.com/kb/829985.