Fix OST File Not Opening in Outlook Issue: Proven Solutions

Summary: A business employee was syncing hundreds of new emails. This process involves writing to the OST file. In the middle of the process, the power cuts out, causing an abrupt system shutdown. This corrupts the OST file’s internal file structure. In this technical blog, we will look at how we can fix OST file not opening Outlook error. In addition, we will look at a professional tool, the Outlook OST Repair Tool, which can help users repair damaged Outlook PST files.

Why does the Outlook OST File Cannot be Opened Issue Occur?

There can be several reasons that lead to this error. A few of them are mentioned below:

• The unexpected closure of the Outlook application, or if the computer crashes, can corrupt the OST file.
• Microsoft Outlook fails to recognize the OST file if the incorrect profile settings are used.
• If the OST file is not in the default folder or is being relocated or renamed, Outlook may not open the OST file.
• The error can occur if any changes are being made to the Exchange account or the mailbox configuration.
• Outlook may experience issues while opening an oversized OST file. This happens if the OST file exceeds its recommended size.

Methods to Fix OST File Not Opening Outlook Error 

There are several ways in which users can fix the issue of the OST file not opening in Outlook. Let’s take a look at them in more detail, one by one.

Fix 01: Restart Both Outlook and your Computer

By restarting both Outlook and the computer, you clear the temporary glitches or any frozen background processes. 

Follow these steps to restart MS Outlook and the system:

1. First, close the Outlook application completely.
2. Also, open the Task Manager by pressing Ctrl+Shift+Esc.
3. After that, in the Processes tab, select the Outlook-related file.
4. Then, select it, click on End Task, and then close Task Manager.
5. At the end, restart your computer and then launch MS Outlook.

Fix 02: Run Outlook in Safe Mode

When Outlook starts in Safe mode, it disables the third-party add-ons. It can fix OST file cannot be opened error that is generally caused by a faulty add-in.

The following are the steps to start Outlook in Safe mode:

1. Close MS Outlook and open the Run dialog box.
2. Now, type: outlook.exe /safe and click OK. This will launch Outlook in Safe mode.
3. Next, go to File > Options > Add-ins and choose COM Add-ins from the Manage drop-down list. Then, click on Go.
4. Uncheck all the add-ins, click on Ok and then restart Outlook. 
5. Unable the add-ins and close and open Outlook.

Fix 03: Set up a New Outlook Profile

If the Outlook profile gets damaged or corrupted, it can prevent users to open OST file in Outlook Error. Generate a new Outlook profile to create a fresh connection with the OST file.

Look at the steps to set up a new profile:

1. Close the Outlook application completely and then open the Control Panel.
2. Now, select Mail and click on Show Profiles.
3. Then, choose Add to create a new Outlook profile and click Ok.
4. Enter the new profile details and complete the setup. 
5. Again, go to the Mail window, choose Always use this profile, and select the new profile.
6. Click on Apply > Ok and open Outlook using the newly created profile.

Fix 04: Disable Cached Exchange Mode and Enable it Again

The Cached Exchange Mode stores the Outlook data in an OST file, from where you can access the emails offline. If it is not working properly, it leads to the “Cannot open OST file Outlook” error. 

Let us look at the instructions to initiate the process:

1. Open MS Outlook and click on File > Account Settings > Account Settings.
2. Then, in the Email section, choose the desired Outlook account and tap Change.
3. Next, under the Account Settings window, uncheck Use Cached Exchange Mode.
4. Click on Next > Finish and close Outlook.
5. Now, reopen Outlook and perform steps 1 and 2. 
6. Check the Use Cached Exchange Mode and click Next > Finish, and restart Outlook.

Most of the time, the Outlook OST file gets corrupted due to many reasons. In such a scenario, it is recommended to use the OST File Recovery to fix OST file not opening Outlook error. This tool repairs the damaged OST file and recovers the emails and other metadata. It also allows users to save the recovered data in several formats, such as MSG, PST, MBOX, and more. 

Simple steps to begin repairing the corrupted OST file:

1. Start by downloading and installing the tool on your system.
2. Then, navigate to Open to select the desired OST file.
3. After selecting the OST file, choose the preferred Recovery mode and click Ok.
4. Once the scanning is completed, click on the Ok button to save the recovered data. 
5. Finally, click on the Ok button after saving the recovered data.

Conclusion

To conclude, this blog has everything you need to know about how to fix OST file not opening Outlook error. We have also mentioned the reasons why this error might have occurred. The manual solutions can be used only when the OST file remains active. But, if it is unsuccessful, use the professional OST File Recovery Tool to repair the OST file data and metadata.

Also Read: Outlook OST File Too Large

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