Outlook Data File Cannot Be Accessed? Here’s How to Fix it!

A while back, when I was working on MS Outlook, I got an error about the accessibility issue of its OST file. Ideally, OST (Offline Storage Table) files are extremely important as they can help us access Outlook data without an active internet connection. Though, if Outlook cannot access the OST file or if it has been corrupted, then you can encounter unwanted problems. In this post, I will let you know what to do if the Outlook data file cannot be accessed on your system.

Outlook Data Accessibility Error Banner

Part 1: Common Accessibility Errors with Outlook

Before we diagnose this problem, it is important to have a look at some of the common accessibility issues encountered in Outlook.

  • The OST file can’t be located or found.
  • The set of files and folders in Outlook can’t be displayed.
  • The OST file is already in use by any other application.
  • The OST file is locked or not accessible to the user.
  • An instance of the OST file is still running or being accessed by another user.
  • Close any other application that is using the OST file.
  • Can’t locate the file path or storage for the OST file.
  • The default OST file is already in use and can’t be displayed.
  • Something went wrong with Outlook, and it can’t load the requested OST file.
MS Outlook Error

Part 2: Why Outlook Cannot Access an OST File?

As you can see, there can be several errors leading to the Outlook data file cannot be accessed problem. Therefore, if you also cannot access an OST file in Outlook, then try to diagnose the issue as it can happen due to the following reasons:

  • Inaccessibility: Chances are that the OST file that you want to access might not be present at its original location (could be deleted or moved).
  • File Corruption: You can also get this error if the OST file has been corrupted by any other application or a virus.
  • Unauthorized Access: If you are not the Administrator or don’t have the respective right to access the OST file, then it could lead to its inaccessibility issue.
  • Syncing Issues: The problem can also be caused due to any syncing error between Outlook, Exchange, or your mailing server.
  • Corrupt Add-ins: At times, even unwanted or corrupt plugins (Outlook add-ins) can also cause this issue.
  • Other Reasons: Besides that, the issue can arise due to a slow network connection, third-party firewall, server problems, data incompatibility, and so on.

Part 3: How to Solve the “MS Outlook OST File Cannot Be Accessed" Problem?

Great! Now when we have covered all the basics, let’s learn how to fix the Outlook data file that cannot be accessed by implementing the following solutions.

Method 1: Turn off the Compatibility Mode in Outlook

Just like other installed applications in Windows, Outlook also supports a compatibility mode. Sadly, if the mode has been enabled, then it can cause issues with the accessibility of the saved OST file.

Therefore, if you cannot access an OST file in Outlook, then you can browse to the location of the Outlook.exe file. You can directly go to its location or look for it from the search option on the taskbar.

Search Outlook EXE File

Great! Once you have found the Outlook.exe file, right-click, and go to its properties. After getting the Properties window, just go to the “Compatibility” tab and make sure the “Run this program in Compatibility Mode” option is disabled.

Outlook Compatibility Mode Disable

Afterward, you can try to relaunch the Outlook application and access the saved OST file without any trouble.

Method 2: Get Rid of Faulty Outlook Add-ins

As I have listed above, if Outlook cannot access OST files, then the issue could be with an installed plugin. Thankfully, you can easily remove any installed add-in from your Outlook account. Just launch Outlook and go to its File > Options > Add-ins at first.

Check Outlook Add-ins

Now, in the Outlook Options window, just go to the “Manage” section, and select “COM Add-in” from the list. This will display a list of the installed add-ins, letting you uninstall any plugin from Outlook. Just select any add-in of your choice and click on the “Remove” button to disable it.

Remove Outlook Add-ins

Method 3: Turn off the Exchange Cached Mode for your Account

At times, the Outlook data file cannot be accessed issue is caused by syncing errors between Exchange and Outlook. To overcome this, you can just turn off the cached mode in MS Exchange.

Just go to Control Panel > Mail > Email Accounts, select your preferred account, and click on the “Change” button. From here, you can just visit the Advanced Settings of your account and disable the “Exchange Cached Mode” feature.

Disable Exchange Cache

Method 4: Use Scanost.exe to Repair the OST File

Needless to say, if the OST file that you are trying to access has been corrupted, then you would encounter accessibility issues with it. The good news is that Windows provides an inbuilt option to fix an OST file with the Outlook Inbox Repair tool.

You can first locate the Scanost.exe file on your system, which is mostly present at C: > Program Files > Microsoft Office. Once you launch the Scanost.exe file, you will get the interface of the Outlook Inbox Repair tool. You can now browse and load the OST file to repair and fix it without any hassle.

Outlook Inbox Repair Tool

Method 5: Repair the Installed Outlook Application

Another reason for the Outlook data file cannot be accessed issue can be related to a corrupt application. In this case, you can simply run a Windows troubleshooter to fix the installed Outlook application.

You can go to your system’s Settings > Apps and Features, and simply select the installed MS Office application. From here, you can choose to Modify the installed MS Office app.

Modify MS Office App

As it will list options to reset or repair MS Office, you can click on the “Repair” option. This will open a new wizard that you can follow to perform a quick or online repairing of the installed Office applications.

Repair MS Office App

Method 6: Convert the Corrupt OST File to Another Format (like PST)

Lastly, if you cannot access an OST file in Outlook, then you can try to export it to any other application instead. To do this, you can take the assistance of Stellar OST to PST converter.

Simply launch the Stellar OST to PST Converter and load the corrupt OST file on it. Afterward, you can start the conversion process that would export all the data in a PST format without any complications. In the end, you can preview your data, export the PST file, and open it in any other application like Thunderbird, Mail Spring, Mail Bird, and so on.

Stellar OST to PST Converter

I’m sure that after reading this post, you would be able to resolve the Outlook data file cannot be accessed issue. Whenever Outlook cannot access an OST file, I usually disable any firewall or get rid of unwanted plugins. Besides that, if you also cannot access OST files in Outlook, then you can try to repair it or simply convert it to a PST format. In this way, you can access your data on Outlook or any other email provider easily.

Other popular Articles From Wondershare