Errors have been detected in your .ost file in Outlook

  • Article
  • Applies to:
    Outlook 2019, Outlook 2016, Outlook 2013, Outlook for Microsoft 365

Original KB number:   3186812

Symptoms

In Microsoft Outlook 2013 or later versions, you receive the following error message:

Errors have been detected in the file C:\Users<name>\AppData\Local\Microsoft\Outlook\user@org.com.ost

When you examine the application event log, you find an event with ID 2000.

Cause

Corruption is detected in your offline Outlook Data File (.ost).

Resolution

To resolve this issue, delete your .ost file and that you let Outlook redownload the information from the server that is running Microsoft Exchange Server.

  1. Close Outlook.

  2. Browse to the following location:

    %localappdata%\Microsoft\outlook

  3. Find the .ost file that the error message reported to have errors, and then delete it.

  4. Start Outlook.

More information

In earlier versions of Outlook, we previously recommended that you use the Scanost.exe tool for errors that occur with your offline Outlook Data File (.ost). The Scanost.exe tool is no longer available starting in Outlook 2010. We now recommend that you delete your offline Outlook Data File (.ost) and that you let Outlook redownload the information from the server that is running Exchange Server.

You can use the following steps to review the Application event log:

  1. In Control Panel, open Administrative Tools.
  2. Double-click Event Viewer.
  3. In the left pane, select Application under Windows Logs.
  4. In the Actions pane, select Filter Current Log.
  5. In the Filter Current Log dialog box, enter 2000 and then select OK.