Outlook is Using an Old Copy of Your Data File (.ost) – How to Fix It

Introduction

Are you facing the issue when your Outlook is using an old version of your Outlook data file (.ost)? If you’re getting a similar error in Outlook, you are in the right place to know a quick way to solve this issue. This guide helps you to fix the “Outlook is using an old copy of your OST” problem in a few simple steps.

Many Outlook users see an error when they try to open an Outlook OST file, and they see an error notice that says, “Outlook is using an old copy of your Outlook data file.” This shows that your Outlook OST files may become damaged or corrupted because they are not properly syncing or for any other reason.

And, when you can’t get to the data in your MS Outlook mailbox, these conditions are really frustrating. You don’t need to worry because the solution to this problem is really simple. In this article, I show you the best ways to fix the Error “Outlook is using an old copy of your data file”.

Common Causes of Outlook Issues are Using an Old Copy of the OST File

• One of the primary causes of this error is a corrupt or damaged Outlook data file.
• Moving the OST file or changing its location without updating Outlook settings.
• Problems synchronising data between the OST file and the mail server.
• The size of your Outlook data file (.ost) has exceeded its limit.

How to Fix Outlook Old Copy of Data File (.ost) Error

Using an old copy of your Outlook OST file is the best way to fix this Outlook problem. To do this, you need to modify its format and make its data easy to get to. There are several ways to resolve this error. Below, I mentioned the top 3 methods to fix ‘Outlook Is Using an Old Copy of Your Data File (.ost) Error’.

Method 1: Resolve Outlook OST Error by Deleting

If Outlook isn’t working right, one of the first things you should do is delete the broken OST file. But first, make sure the file isn’t hidden on your computer before you remove it. It depends on whether you’re using Windows 7 and Windows 10, and on how to unhide the OST file. Let’s go through how to unhide the file in each version. After that, I’ll teach you how to safely remove the damaged OST file from Outlook.

How to Unhide OST Files in Windows 7:

• Open File Explorer.
• Click Organise in the top-left corner and select Folder and search options.
• In the View tab, choose Show hidden files, folders, and drives.
• Click Apply and then OK.

How to Unhide OST Files in Windows 10:

• Open File Explorer.
• Click the View tab at the top.
• Check the box that says Hidden items.

Once you’ve done this, you should be able to see the hidden OST file in its location. If the issues are still not solved, move to the next method.

Method 2: Disable and Re-Enable Cached Exchange Mode in Outlook

When Outlook says “Outlook is using an old copy of your data file (.ost),” reset Cached Exchange Mode to rebuild and sync your mailbox.

With Cached Exchange Mode, you can access a .ost file on your PC even without the internet. Usually, turning this feature off and on again fixes sync issues with outdated or broken files.

Steps to Disable Cached Exchange Mode:

(For Outlook 2016, 2019, 2021, 2024 & Microsoft 365 on Windows)

• Open Outlook on your computer.
• Click on “File,” then “Account Settings,” and then “Account Settings” again.
• From the Email tab, pick your Exchange account.
• Choose Change.
• You should not click the box next to “Use Cached Exchange Mode.”
• Click “Next” and then “Finish.”
• Close Outlook and then open it again.

Steps to Re-Enable Cached Exchange Mode:

After restarting Outlook:

• Select File > Account Settings > Account Settings.
• Choose your Exchange account and then click Change.
• Select Use Cached Exchange Mode.
• Click Next and then Finish.
• Close and open Outlook again.

Outlook will now make a new OST file and start synchronising your inbox with the server.

Method 3: Use the Outlook Built-in Tool to Solve OST Error

If you receive the error message “Outlook is using an old copy of your Outlook data file (.ost) from 2013, 2016, and below editions,” it signifies that the OST file is broken or corrupted. There is a utility in Microsoft Outlook called “SCANPST.EXE” that can help with this. It tries to fix the broken OST file and get rid of the error message. But it can only fix small problems. You should hunt for another method if your OST file is very corrupt.

The Expert Way to Fix

We can see that the procedures above are utilized to fix the Outlook problem that happens when an old OST file is used. Now we can see how an expert would fix the OST problem by changing the format of the file to one that works. Any good OST to PST converter software lets you receive all of your OST data and save it in PST format so you can open it again in MS Outlook.

If the OST file is too large, it can be difficult to retrieve emails. But with the right program, you can rapidly get your data back from any huge, damaged, or corrupted Outlook OST files.

Steps to Convert OST Files to PST Format

1. Download and run the OST Converter.
2. Browse and upload the .ost files.
3. Take a complete preview of the data.
4. Choose the .pst file type from the list.
5. Now, select the desired path for storing data.
6. Lastly, Hit the Convert Button.

Conclusion

All available solutions for how to solve Outlook are utilising an old copy of your Outlook data file. Convert OST in Outlook 2024, 2021, 2019, 2016, 2013, 2010, etc. When the OST file gets corrupted and can’t be opened, this is one of the most common mistakes that happens.

So, the article provided the best way to get around this error notice. I hope these fixes will help you solve the problem. But based on what I’ve seen, you should make a healthy PST file first and then do all the steps on the list.