Email Repair
Windows 11 KB5078127 Out-of-Band Update Fixes Outlook Crashes Issue
July 24, 2026| 5 min read
Summary: If you’re getting the "PST is not an Outlook data file" error, you can first try some workarounds, such as check the PST file attributes, copy the file to another location, and check the file size. If these don’t work, then check and fix disk errors, create a new profile, or repair the PST file. In this guide, we will explain these solutions in detail to help you resolve the error. If the PST file is severely corrupted, use Stellar Repair for Outlook to repair it with complete integrity.
Free Download 100% SecureThe error “PST is not an Outlook data file” occurs when your email client fails to recognize or access the data (.pst) file. The error may also appear with a message such as:
“Cannot display the folder. Microsoft Outlook cannot access the specified folder location. The operation failed. An object cannot be found.”
Below, we will look into the reasons that may trigger this Outlook data file error and provide the solutions to fix it.
This error may occur due to various internal and external factors. Some common ones are given below:
Corruption in PST File
A damaged or inconsistent PST file is one of the common causes of this error. Corruption can occur due to an interrupted Outlook operation, improper system shutdown, disk errors, or other reasons.
PST File is in Read-Only Mode
If the PST file is marked as read-only, Outlook may be unable to access or write to it, thus triggering the error.
Incorrect File Location or Permission Issues
Outlook may fail to access the PST file, if it is located at another location or user account doesn’t have the required permissions on the file or the folder where it is stored.
Damaged Outlook/MS Office Program Files
If your Outlook or MS Office program files are damaged, then you may encounter various errors, including this Outlook data file error.
Faulty or Incompatible Add-ins
If you’ve installed any incompatible add-ins in Outlook or some add-ins become faulty, then they can interfere with the application’s functionality, causing such errors.
PST is Stored on Network Share or Drive
If you’ve stored the PST file on a network drive, then Outlook may fail to access the file if there are any connectivity issues.
Bad Sectors or Issues on the Disk
If there are bad sectors or any other issues on the disk where the PST file is stored, then Outlook may fail to read or access the file and trigger the error.
Oversized PST File
When PST becomes very large, Outlook may fail to read or write the data on it, causing this error.
Corrupt Outlook Profile
Corrupt or damaged profile can also prevent Outlook from properly accessing the PST file.
Here are some troubleshooting steps you can perform to quickly resolve the error:
If the PST file is set to read-only, Outlook may be unable to write data to it, resulting in the error. To fix this, locate the PST file, right-click on it, and select Properties. Under Attributes, check that Read-only and Hidden are not selected. If any of the options are selected, uncheck it and select Apply > OK.
If the PST file is stored on a network drive, connectivity or network issues can prevent Outlook from accessing the file. In this case, you can copy the file to the local hard drive and set the new file location as default in Outlook.
When the PST file becomes very large or oversized, Outlook may fail to read or write the data properly. To check its size, right-click on the file and select Properties. If the size of the PST file is large, then you can reduce its size.
If the above quick fixes didn’t work for you, follow the below-given methods to troubleshoot and resolve the error.
An outdated version of Outlook may have bugs or compatibility issues that can affect access to the data file. If you’re not able to access the Outlook options, you can check and install the updates through another Office application, such as Word or Excel. For this, open the application and go to File > Account > Update Options > Update Now. After installing the available updates, restart your computer and check if the issue is resolved.
Bad sectors or other errors on the drive, where your PST file is stored, can prevent Outlook from accessing or reading the file. Therefore, you can check for any disk errors and resolve them to fix the issue. The steps are as follows:
In the above command,
After this, restart the system, launch Outlook, and then check if the error is resolved.
Faulty or incompatible add-ins can interfere with Outlook’s functionality and may cause issues and errors. To check whether an add-in is causing this error, start the application in Safe Mode. If the error does not appear in this mode, this confirms that an add-in is causing the problem. You can disable the add-ins in Outlook. Then, enable the add-ins one at a time to identify the problematic one.
Incorrect configuration settings or a corrupted profile can prevent Outlook from accessing the PST file, causing the PST file is not an Outlook data file error. Creating a new Outlook profile resets all configuration settings and can resolve the profile-related issues.
Damaged or corrupted Outlook program files can prevent the application from accessing the PST file. You can use the Repair option in Microsoft Office to fix the problem. Here’s how to do so:
If repairing the program does not resolve the issue, you can reinstall Microsoft Office.
Corruption in the PST file is one of the common reasons for the “PST is not an Outlook data file” error. The application may fail to recognize or access the PST file when its internal data structure is damaged. You can use the Inbox Repair Tool (ScanPST.exe) to repair the file.
Though Scanpst.exe can repair corrupt PST file, it has certain downsides, such as:
If ScanPST fails to repair the PST file, you can use Stellar Repair for Outlook - a more powerful PST repair tool. The ScanPST alternative can efficiently repair the PST files regardless of the size and the level of corruption. It can recover emails and other mailbox items while preserving the original folder structure and hierarchy. It also allows you to preview the recoverable data before saving it to a new PST file. This tool also supports recovery of deleted mailbox items from the file. It is compatible with Outlook versions 2024, 2021, 2019, 2016, and earlier.
The “PST is not an Outlook data file” error occurs when opening, importing or attaching a PST file in Outlook. You can resolve the error by following the troubleshooting methods discussed in this guide. If the PST file is corrupted, use the Outlook ScanPST.exe tool to repair it. If it fails to repair the file, use Stellar Repair for Outlook. It can repair severely corrupted PST files and restore the mailbox items to a new PST file, helping you regain access to your Outlook data.
If you want to repair PST file without ScanPST, you need to use a third-party PST repair tool, such as Stellar Repair for Outlook. This tool can repair severely corrupted, damaged, or encrypted PST files without any file size limitations.