Solved Error – Outlook OST File Cannot be Opened Windows

This article explains Why Outlook OST File Cannot be Opened on Windows and how to fix this issue. We have described the various methods to fix this error. Here, we also suggest a reliable OST Recovery Tool, which will help users to recover mailbox data from corrupt or inaccessible OST files. Read this blog to know more. 

OST file is an offline Outlook data file to store the copy of mailbox items and is created when you establish an Outlook connection with the Exchange server. Ost file allows users to work in offline mode like composing, deleting, writing, and it will update all these once you establish a proper internet connection. But sometimes, users face issues while opening these OST files, and Outlook shows them an error message: Outlook OST File Cannot be Opened. There are different reasons behind this issue like MS Outlook is not updated, the add-in is conflicting, or the Outlook data file becomes corrupt or damaged. So, let’s learn the methods using which you can easily resolve or fix Outlook OST File Cannot be Opened issue.

Methods to Solve Outlook OST File Cannot be Opened Error

Here are the top manual methods to fix Outlook OST File Cannot be Opened issue. You can try the native solution, which will help you to make the OST files accessible again, but if your OST file is corrupt or damaged, then you need to use an advanced professional Tool, i.e., OST Recovery Tool.

Method 1: Close all the Outlook Processes 

If you are using MS Outlook on a different system or performing multiple tasks simultaneously, then you need to close all the running tasks:

1. Right-click on the Taskbar menu and go for the Taskbar menu.
2. Select the Task Manager Click on the Processes tab.
3. Here, you will find that MS Outlook is in the running stage.
4. Finally, select it and click on the End Task button.

Method 2: Try to Repair Outlook & Install Updates

If your Outlook application is not working properly, an Outlook OST File Cannot be Opened issue may occur. Thus, it would help if you repaired Outlook using the Office Repair option. 

Steps to Repair Microsoft Outlook

1. Right-click the Windows icon and choose the Apps and Features from the list.
2. Here, select Microsoft Office and click on Modify.
3. Choose the option How would you like to repair Office programs?
4. Click on the Quick or Online Repair option.
5. After that, click on the Repair button.
6. Once the process is completed, restart your system.
7. Finally, your Outlook application is ready to use.

To fix this issue, you also ensure that your Outlook application is updated; if not, then follow the steps to install new Outlook updates:

1. Start Outlook and click on the File.
2. Open the Office Account section and go under Product Information.
3. You need to click on the Install Updates>>Upgrade Now Option.

Method 3: Turn Off the Cached Exchange Mode

1. First of all, close your running Outlook application.
2. Search for the Control Panel and open it.
3. Click on Mail and select Email Accounts.
4. Check the email address displaying the username.ost error.
5. Here, click on the Change.
6. You need to disable the Use Cached Exchange Mode option.
7. Click Next>> Finish to complete the process.

Method 4: Disable or Remove an Add-in In Outlook

When you add an add-in to your Outlook application, it will help you to customize the app according to your requirement. However, attackers can use add-ins to harm your computer and are sometimes responsible for different Outlook errors like Outlook OST File Cannot be Opened. Perform the below to steps to disable Outlook Add-in:

1. Click on the Windows icon and enter Run.
2. Open it and type outlook.exe/safe to run the Outlook application in safe mode.
3. Start Outlook and click on the File tab.
4. Go to the Options and opt for the Add-ins. 
5. In the Outlook opening options, search the Manage section.
6. Go to the COM Add-ins option in the drop-down menu, and click Go.
7. Here, you will have to unselect all add-ins and click OK.
8. Open the Outlook application and run it in normal mode.

Method 5: Fix Issue By Creating a New Outlook Profile

A corrupt or inaccessible Outlook profile is also responsible for the Outlook OST file cannot be opened. Therefore, you need to delete your existing profile and create a new one to troubleshoot the issue.

1. Start Outlook and click on the File.
2. Select Account Settings >> Manage Profiles.
3. Here, choose the Show Profiles option and click Add.
4. In the Profile Name tab, enter a name for the profile, and click OK.

Method 6: Repair OST File to Fix Outlook OST File Cannot be Opened Error

One more reason why the Outlook OST file is not opened is that your OST file may be corrupt or damaged. Thus, you can use the ScanPST.exe tool to repair the Offline Outlook data file.

1. Repair your Outlook OST file Using Inbox Repair Tool
2. Start the Scanpst.exe on your system.
3. Click Browse to select the OST file.
4. Then click Start to scan the file corruption issue.
5. If the utility detects some issues, then click on the Repair button.
6. Within a few minutes, your OST file is ready for use again.

But What if the ScanPST.exe tool can’t repair your Outlook OST file due to its large size or severe damage? In such a case, you need to look for another solution that will help you to fix the OST file corruption, damage or inaccessibility issue.

Method 7: An Automated Tool to Repair Outlook OST file

If none of the methods works, you can rely on the Aryson OST Repair Tool. It is the best software to recover the mailbox email message, contact, calendar, tasks, journals, etc., from the corrupt or damaged OST file. Additionally, it includes the feature to export corrupt or inaccessible OST data to Outlook PST files, MSG, DBX, EML, MBOX and others.

Steps to Resolve Outlook OST File Cannot be Opened Issue

1. Download and Run the OST Repair Tool.
2. Click Open and browse the OST file from your system.
3. Choose the Recovery mode according to the corruption level.
4. Click Ok to start the scanning process.
5. Here, select the folders and preview their details if needed.
6. Click Save and select the saving format as PST or others.
7. Choose the required built-in features and click Ok.
8. Finally, your added OST file is repaired successfully.

Conclusion

In this post, we have understood the different methods to resolve the Microsoft Outlook OST file cannot be opened problem in Outlook 2019, 2016, 2013, and earlier versions. However, if the OST file issue occurs due to corruption or damage, then for that, we suggest this best OST Recovery software, which is created with the motive to fix all issues related to OST files.

Realted Post