Incomplete search results may occur in Outlook when a PDF iFilter is installed

Applies to: Outlook 2016Outlook 2013Microsoft Outlook 2010 More

Symptoms


  • When you use instant search in Microsoft Outlook you receive a message that states "No matches found" or you receive an InfoBar message that states "Search results may be incomplete because items are still being indexed."
  • If you check the status of indexing, you see there are still items remaining to be indexed in the Indexing Status window.
  • When you review the events in the application event log, you see items with the following parameters:
Event ID SourceTask CategoryDescription
10023SearchGathererThe protocol host process <PID> did not respond and is being forcibly terminated {filter host process 6104
10024SearchGathererThe filter host process <PID> did not respond and is being forcibly terminated.


Cause


This problem occurs when a PDF iFilter stalls the Windows Desktop search indexer, causing frequent re-indexing of Outlook items.

Resolution


To resolve this problem, please update any applications that offer PDF file functionality with the latest patches. Then, follow these steps to rebuild the index.
  1. In Control Panel, click Indexing Options.

    If Indexing Options does not appear in Control Panel, type Indexing Options in the Search Control Panel text box, and then click the Indexing Options search result.
  2. In the Indexing Options dialog box, click Advanced.
  3. Click Rebuild.
  4. Click OK in the Rebuild Index dialog box.