Outlook OST File Cannot be Opened in Outlook: Top Solutions

Most of the users claimed that they had upgraded their Outlook email server.  One common problem after the upgrade users face is an error message “Outlook OST File Cannot be Opened in Outlook.” This means that after the upgrade, users cannot open their OST files within Outlook. Several users have this problem, and that limits access to offline emails and synchronization with the server. To resolve the issue where the OST (Offline Storage Table) files cannot be opened in Outlook, we suggest several methods. And a specialized DRS OST Recovery tool to bypass this issue easily.

Reasons Behind Outlook Cannot Open OST File

Here are some common reasons why Outlook cannot open an OST file:

  • The OST file may be corrupt.
  • The OST file might not be compatible with the version of Outlook being used.
  • You are using an outdated version of Outlook.
  • Problems with the Outlook profile or user account settings.
  • Insufficient permissions or restrictions on the OST file.
  • A huge OST file can become problematic.
  • Issues during synchronization with the mail server.
  • Conflicts with antivirus software or other applications.

 

Addressing these issues typically involves repairing the OST file, updating Outlook, or adjusting settings.

Ways to Resolve the “Outlook .ost Cannot be Opened”?

The majority of Outlook errors are fixed either by making suitable changes in the configuration settings or by repairing the corrupt Outlook data file. 

We will describe the two methods to resolve this issue: 

  • Manual method to resolve “File .ost cannot be opened”
  • Resolve “Outlook cannot open an OST file” using the OST recovery Tool

Manual Method to Resolve “The file .ost Cannot be Opened”

To resolve the ‘OST Files Cannot Be Opened’ error manually, follow these steps:

Verify File Compatibility:

  • Ensure that the OST file is compatible with the version of Outlook you are using.

Repair the OST File:

  • Use the Inbox Repair Tool (Scanpst.exe):
    • Locate and run Scanpst.exe. (Found in the Office installation directory)
    • Browse and select the OST file to scan.
    • Click Start to begin the repair process and follow the prompts.

Recreate the OST File:

  • Delete and rebuild the OST file:
    • Navigate to the OST file location (C:\Users\[Username]\AppData\ Local\Microsoft\Outlook\).
    • Rename or delete the existing OST file.
    • Restart Outlook, which will automatically create a new OST file and resynchronize with the server.

Check and Update Account Settings:

  • Verify Configuration:
    • Go to File, and after that, Account Settings.
    • Ensure that all email account settings are correct and up-to-date.

Check Permissions:

  • Ensure Proper Access:
    • Navigate to the OST file location.
    • Right-click the OST file and select Properties.
    • Check the Security tab to ensure that you have the necessary permissions.

Update Outlook and System:

  • Install Updates:
    • Ensure that both Outlook and your operating system are updated with the latest patches and updates.
    • Install available updates, and then restart your computer.

Disable Conflicting Software:

  • Check for interference:
    • Temporarily disable antivirus or other security software to see if it resolves the issue.
    • Re-enable software after testing.

Consult IT Support:

  • Seek Additional Help:
    • If the issue persists, contact IT support or consult Microsoft’s support resources for further assistance.
    • Visit Microsoft’s Support and follow the instructions to report the issue.

By following these steps, you can manually troubleshoot and resolve the error preventing your OST file from being opened in Outlook.

Restrictions on Solving “Unable to Open OST File in Outlook” Manually

Manually resolving the “Unable to Open OST File into Outlook” error can be effective. There are some limitations to this approach:

  • It might lead to data loss if not done carefully.
  • This process can be complex.
  • The manual process can be time-consuming.
  • The Inbox Repair Tool (Scanpst.exe) has limitations in addressing severe corruption.
  • There is a risk of incorrect configuration.
  • Manual processes are inclined to user errors.

Although many of the issues regarding  “OST File cannot be opened” can be resolved by using these manual methods. The limitations to this are the possibility of data loss, different levels of difficulty involved, and partial resolution. More serious or remaining issues will need the intervention of professional tools or support.

Resolve “Outlook Cannot Open OST File” Using the OST Recovery Tool

DRS OST Recovery is the best online tool to deal with corrupted and damaged OST files and helps users fix the issue with ease. Also, it has an advanced scan feature to easily locate Outlook OST files. In this utility, multiple recovery modes are available to fix any level of OST corruption. Display the preview of the recovered Outlook file content to reduce the chance of error. It supports both ANSI and UNICODE file encryption systems. This tool is available for both Windows and Mac OS. Now, move to the next segment, which is the working of tools.

Simple Steps to Resolve OST File Cannot be Opened Issue

Here are the simple steps of the utility to resolve the issue seamlessly:

  1. Download, install, and launch the DRS OST Recovery Tool on your system. Run as an administration
  2. After that, click on the Open option at the top left corner.
  3. Under this open option, Browse the OST file from your local storage.
  4. Now, use the additional feature according to your needs.
  5. Now, with the help of the left panel, preview your IOST file data to reduce an error.
  6. After that, mark check the required file folder from the folder list.
  7. Now, click on the Save option to save the file in another file format.
  8. Next, provide the desired path to save the file.
  9. In the end, click on next.

Related Post: Cannot Open Default Email Folders.

Conclusion

In this article, we outlined several methods to fix the error ‘ost file cannot be opened’. This issue often arises because the OST file is corrupted or orphaned. To recover and restore your email data, recover the OST file using the DRS OST Recovery tool, then import the OST file into another file format.

Frequently Asked Questions

Q.1 Why does Outlook show the error “OST file cannot be opened” after a server upgrade?

Ans: After a server upgrade, Outlook may fail to recognize the existing OST file because of synchronization changes or profile mismatches. In many cases, the old OST file becomes incompatible with the upgraded server environment.

Q.2 Can a corrupted OST file stop Outlook from opening completely?

Ans: Yes, if an OST file becomes severely corrupted, Outlook may not open or may crash during startup. Corruption often occurs due to sudden shutdowns, large file size, or sync interruptions.

Q.3 Is it possible to access OST data if Outlook cannot open the file?

Ans: Yes, even if Outlook cannot open the OST file, the data can still be recovered using a professional DRS OST recovery tool that extracts emails, contacts, and folders safely.

Q.4 Does recreating an OST file delete existing emails?

Ans: Recreating an OST file does not delete server-based emails, but locally stored or unsynchronized data may be lost. That is why backing up or recovering the OST file before deletion is recommended.

Q.5 Why does ScanPST fail to repair some OST files?

Ans: ScanPST has limitations and cannot fix severely damaged or orphaned OST files. It works only for minor corruption and may fail if the file size is large or deeply corrupted.

About The Author:

I, Aaradhya Jain, a technical content writer at DRS Solutions, specializes in delivering clear, practical guides on data management, migration, and recovery tools. With a detail-oriented and user-first approach mindset, I transform complex processes into actionable insights for IT professionals and decision-makers.

© Copyrights 2018-2026 DRS Softech - All Rights Reserved.