BitResQ » How to Fix OST is Not an Outlook Data File Error Instantly?

How to Fix OST is Not an Outlook Data File Error Instantly?

Shubham Dixit   
Published: May 12, 2022 • Tips • 5 Minutes Reading

While working suddenly if the OST file becomes inaccessible. This might happens because of losing access to the OST file. So, it throws the OST is not an outlook data file error. In this situation, the best thing you do is to fix the OST file issue as earliest possible. Otherwise, you may lose the data of the OST file.

So, to prevent the losses, we are here to provide you best possible solutions. Sometimes, you get a warning but mostly it does not provide any warning. Here, you will learn solutions if you cannot start Microsoft Outlook because the file is not an Outlook data file (.ost).

Read More: Quick Solution to Repair Corrupted OST File

Let’s just understand the basic causes which affect the OST file.

What are the Causes Behind “OST File is Not an Outlook Data File” Error?

This said errors may appear because of multiple reasons, but let’s know about it first –

  • Sometimes, the OST file becomes inaccessible when the OST file size limit increase. Which becomes the cause of such errors.
  • Moreover, if there is any kind of virus attacks on the system, then it affects the OST file. Eventually, the OST file issue appears.
  • Likewise, crashing in the system directly is a different reason when Outlook, Hotmail, or Exchange throws this error.
  • Some major errors can be the reason why Outlook cannot access the OST file.

Just like these reasons, there are many other reasons. So, now, let’s just know the solutions to fix the OST file error.

Different Approaches to Fix OST File Issue

However, you cannot access the OST file like the PST file on other platforms. As the OST file requires the authorization. Therefore, when you face such OST file errors you must use these tactics –

  1. Fix Outlook Profile Manually
  2. Create a New Outlook Profile Manually
  3. Automated Method
Read More: Best Solution to Open Orphaned OST File in Outlook

First, let’s just know about the manual methods to fix the OST file issues.

Fix Microsoft Outlook Profile Manually

If there is any corruption in the Outlook profile then this affects the OST file. So, to resolve such corrupt files you can use the feature of the Outlook –

  1. First of all, in any Outlook 2010, 2013, 2016, or 2019, go to File > Account Settings > Account Settings
  2. Then, in the Account Settings box, choose the Email tab. Here, select the required account which is showing errors
  3. After that, tap on the Repair button
  4. Eventually, to finish the task, tap on the Finish button.

Once the entire process is done, just restart the Outlook application. Then, check whether the OST file error has been solved or not.

Create a New Outlook Profile To Fix OST File Errors

To make a new Outlook profile and resolve OST is not an outlook data file error, follow –

  1. First of all, open Control Panel, search, or tap on the Mail button
  2. After this, mouse-click the Show Profiles radio button
  3. Here, click the Add and then provide any new profile name. Click the OK button to proceed
  4. Now, in the Add Account wizard, provide your name, email ID, and password and tap on the Next button
  5. In the next step, select the New Profile from the options and enable Always use this profile. Just after this, choose the Prompt for a profile to be used option to move further. Lastly, hit the OK button to finish the task.

Best Automated Way to Fix OST is Not an Outlook Data File Error

There can be chances when the said error didn’t solve using the above method. So, in this case, you should choose an automated and reliable solution. One of the best and a professionally tested program is BitResQ Outlook OST Recovery Wizard.

It will fix all including minor or major errors of the OST file. With this application, you can easily resolve the error of Exchange.ost, Outlook.ost, Hotmail.ost files. Later on, preserves the entire data from the inaccessible OST file.

Moreover, it is a tool based on the top technologies, so the entire data integrity remains the same as earlier. Using this advanced tool, you will get back a healthy OST file with no corruption issues.


We all know the working of the OST file, at times, you may also face errors while working. The OST is not an outlook data file error is one of them. Therefore, we have shared manual and automated solutions here. You can check the OST file after performing the manual methods. But, if the error is still there and it cannot start Microsoft Outlook.ost, Exchange.ost, Hotmail.ost. Hence, using the mentioned automated software you can resolve the file is not an Outlook data file (.ost). Thus, we highly recommend you to go with the professional method as described above.