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Errors have been Detected in the File Outlook(OST)

  Mark Regan
Mark Regan
Published: April 29th, 2025 • 7 Min Read

Microsoft Outlook is a widely used email client that manages communication, calendars, contacts, and more for millions of people. However, sometimes users encounter the error message: Errors have been detected in the file Outlook(OST) after deleting Office 365. This error mostly appears when Outlook OST corrupted or inaccessible.

An OST File allows to work offline and sync changes once a connection to the Exchange Server is reestablished. When corruption occurs, Outlook may fail to open, synchronize data incorrectly, or crash unexpectedly. Signs you are facing errors in Outlook OST file and how to fix by inbuilt Outlook Inbox repair tool and OST Converter to fix it effectively.

Table of Content Hide
  1. Common Causes Behind Errors Detected in the File Outlook(OST)
  2. Signs You Are Facing Errors in Outlook(OST) File
  3. Fix “Errors Have Been Detected in the File Outlook(OST)” Issue
  4. Professional Approach to Fix Errors have been Detected in the File Outlook(OST)
  5. Common Questions
  6. Final Thoughts

Common Causes Behind Errors Detected in the File Outlook(OST)

  • OST files can be corrupted due to software crashes, improper shutdown or failed Outlook processing. A damaged OST file can trigger this error when launching Outlook.
  • Unexpected shutdowns or power failure while Outlook is running can interrupt leading to OST file damage.
  • When Outlook fails to sync with Exchange Server, inconsistency can develop between local OST file and server, resulting in corruption and synchronization.
  • Older versions of Outlook have OST size limitations. When it reaches, it may get corrupted or trigger the error.
  • Malicious software can affect OST file data and disrupt normal Outlook operations, can turn OST file inaccessible mode.
  • If the hard drive has bad sectors or file system errors, it can corrupt any file including Outlook OST file.

Signs You Are Facing Errors in Outlook(OST) File

  • If Outlook freezes, crashes upon startup or closes unexpectedly it could be due to a corrupted OST file.
  • Aside from Errors have been detected in the file Outlook OST you may also see errors like: Cannot start Microsoft Outlook.
  • OST corruption can prevent the display of all data correctly, and users often report missing emails. Contacts, or entire folders.
  • Delayed email sending/receiving, lag when opening items or long startup times can point to issues with OST files.
  • If emails are not syncing between Outlook and Exchange Server, or you’re seeing duplicate messages or outdated folders your OST file may be damaged.

How to Fix “Errors Have Been Detected in the File Outlook(OST)” Issue?

If you are facing Microsoft Outlook Errors have been Detected in the file OST then it’s too curial to repair and recover data from Outlook. So, we have explained the top 5 methods to fix this error effectively.

Method 1. Use Built-in Outlook Repair Tool

  1. First, Close Outlook completely.
  2. After that, Locate ScanPST.exe and launch a tool to browse corrupted OST files.Microsoft Outlook Inbox Repair Tool
  3. Now, Click Start to scan the file and fix it if any issues found.Repair Complete

Method 2. Delete and Recreate OST File

If repairing an OST file doesn’t work, you can rebuild OST file.

  1. Now, Close “Outlook”.
  2. Next, Navigate to “OST file location”: C:\Users\Username\AppData\Local\Microsoft\Outlook\
  3. Then, Delete the “damaged OST file”.
  4. Finally, Restart automatically to “Recreate your OST file”. (But sometimes Errors have been detected in the Outlook OST after deleting).

Method 3. Repair Microsoft Outlook Installation

  1. Open “Control Panel” and Click on Programs.Open Control Panel
  2. Now, Select “Programs and Features”.
  3. Find “Microsoft Office” and right-click on it and select Change.
  4. Browse “Repair” and follow on-screen instructions.

Method 4. Restore OST File from Backup

  1. If you have a recent backup of the OST file and for the mailbox data.
  2. Restore the backed up OST file.
  3. Replace the corrupted file with the backup copy.

Professional Approach to Fix Errors have been Detected in the File Outlook(OST)

Sometimes, it happens due to oversize, damaged, or OST files getting disconnected from the Exchange Server. To fix this issue, you should use the BitRecover OST to PST Converter, as this software can effectively repair and recover data from damaged OST files. It also allows you to export the recovered data into PST format for easy access in Microsoft Outlook. Click the Download button below and follow the steps outlined in the guide to complete the process.

Steps to Resolve Errors have been detected in the file Outlook(OST)

  1. Download and open “Automated Software” on your system.Errors have been detected in the file outlook.ost fixer
  2. Now, Click on “Convert configure Outlook mailbox data” and click on Next.Select Configure Outlook account
  3. Select “Outlook mailbox folders or subfolders” as you want to export.Select Outlook OST Folders
  4. Choose the “PST file” in the list of Saving options.Choose PST File
  5. Browse destination path, select file size, separate PST per user as needed.Select destination path
  6. Use “Advanced settings for filter” and click on Next to start fix Errors have been detected in the File Outlook OST. start fix Errors have been detected in the File Outlook OST
Remarkable Qualities of Recommended Software
  • It allows you to extract email addresses and extract contacts from OST file.
  • This software is especially created with a simple user interface to easily perform by any professional or individual users.
  • You can also convert OST to EML, CSV, PST, PDF, HTML and many more with maintained results.
  • With this wizard, you can also use filter options such as create PST year wise, date range, from, to, subject, exclude folders, organizer, root folder, exclude empty folder, use Microsoft Graphs and many more.
  • This software can also import OST to Gmail, Thunderbird, Zimbra, Maildir and all IMAP Supported email servers.
Common Questions

How to fix Outlook OST file error?

To fix Outlook OST file error you can use Scanpst.exe to repair the OST file and recreate the Outlook profile. If this error continuously appear then try to repair Outlook installation or OST Recovery for advanced recovery.

How do I fix errors that have been detected in the file in Outlook?

Close Outlook and run Scanpst.exe on the OST file and follow the prompts to repair it. If that fails, delete OST file and relaunch Outlook to automatically create a new one synced from the server.

How to fix OST if it is not an Outlook data file?

This usually indicates corruption. Delete the faulty OST file and relaunch Outlook and it will regenerate OST file by downloading data from the server. Make sure all data synced before deleting the OST file to avoid data loss.

Final Thoughts

Let’s summarize what we have studied in this tutorial. We have learned a basic overview about this error, causes and signs of errors in the Outlook OST file. In addition, we have shared all effective methods to fix Errors have been detected in the file outlook.ost after deleting manually and through alternative solutions. If the manual approach does not work and the errors remain, we recommend you opt for automated software, as it can completely fix “Errors have been detected in the file Outlook.ost” after deletion. This software is definitely reliable for Microsoft 365 or Microsoft Outlook and also offers fully maintained results without losing any information.