[FIXED] Outlook Cannot Open OST File Error

The outlook is an efficient application when it comes to providing an email facility to the users. But sometimes, you might note that a message “ost file cannot be opened” appears on the screen.

Mostly, the corrupted .ost files can lead to error. You won’t be able to access the emails, contacts, events and other important documents. Besides, the improper installation of Outlook is the other reason behind such an error. 

Miscommunication between Outlook and Exchange Server mailbox can trigger this error in Outlook. When you get this error, you won’t be able to open the Outlook profile. So, if you are getting this error, you should fix it at the earliest. 

Here, we are going to discuss the possible solutions that can help you to fix the problem at the earliest.

Possible ways to Solve: Outlook data file cannot be opened

In this section, we are going to talk about the possible methods to fix the corrupted .ost files. You just have to implement the mentioned methods as instructed below.

Method 1: Close the Outlook Related Programs

If you have opened multiple Outlook related programs, then you can come across this error. In that case, you have to close all the Outlook related programs. 

And to end the entire Outlook related programs, you have to follow the below-mentioned steps:

• Close the Microsoft Outlook Program first. And then, right-click on the “Taskbar” Menu.
• From there, tap on the “Task Manager”. Now, move to the Processes tab.
• In the Processes tab, search for the “Communicator, Lync, Outlook and Ucmapi” applications.
• Right-click on these applications and then choose the “End Process” option to close those applications.

Now, after closing all the Microsoft Outlook related programs, check if you can open Microsoft Outlook. And if you are still getting the error then you should move to the next section. 

Method 2: Disable all the Outlook Cached Exchange Mode

If the Outlook Cached Exchange Mode is enabled, you won’t be able to open Outlook. In that case, you have to disable the Outlook exchange Mode to fix this error. 

And to disable that, you have to implement the below-mentioned steps:

• Close all the Microsoft Outlook related programs first. And then move to the “Control Panel”.
• From the Control Panel window, tap on the “Mail” option and then choose the “Email Account” option.
• Move to the Email accounts and then go to the “Email” tab. 
• Next, tap on the “Exchange Account” option. Now, click on the “Change” button.
• Go to the “Offline Settings option and then make sure the “Cached Exchange Mode” option is checked. 
• Now, tap on the “Next” button to complete the whole process.

Now, after disabling the Outlook Cached Mode, you will be able to open Outlook. But if you are still encountering the “ost cannot be opened“ error, then it is suggested to move to the next section. 

Method 3: Disable the Outlook Add-ins

The faulty add-ins in Outlook can create at the time of opening the application. In that case, you have to disable the add-in to fix the error. 

And to do that, you have to follow the below-mentioned steps:

• Hold the Windows and R keys together. This will open the Run dialog box. 
• In the Run dialog box, write “outlook/safe”. Hit the “Enter” button next to open the Outlook enabling the Safe mode.
• Now, tap on the Outlook icon to open it. Hold the Ctrl key and then double -click on the application. 
• A window will appear next on the screen. Tap on the “Yes” button to get to the Safe Mode.

Now, after enabling the Safe Mode, you will be able to disable all the add-in. But even after doing that you fail to get rid of the corrupted .ost files, then you have to proceed to the next mentioned method.

Method 4: Repair the .ost Files Using ScanOST.exe

The ScanOST.exe tool is inbuilt in every device that uses Microsoft. You can scan the corrupted .ost file using this tool. And to repair the corrupted .ost files, you have to follow the below-mentioned steps:

• Close the Microsoft Outlook program first. And search for the “ScanOST.exe” file and double-click on it.
• This application will let you scan the corrupted .ost file to repair. Choose the “OST” file from there.
• If you are not aware of the .OST file, then you have to hold the Windows and R keys together to open the Run dialog box.
• In the Run dialog box, write “%LOCALAPPDATA%\Microsoft\Outlook\”. Now, choose the mailbox from there.
• Now, choose the “Repair Errors ‘ option and then tap on the “Begin Scan” option to start the process.

The whole repairing process might take a while to complete. Wait until the tool repairs the corrupted .ost file. And now, you will be able to open the Outlook application without any hassle. 

Frequently Asked Questions (FAQs)

• How to open the OST File?

To open the OST file, you have to follow the below-mentioned steps:

1. Open the OST file from the device. Next, disconnect the network.
2. Now, open the “Microsoft outlook” application. Go to the File section.
3. Next, go to the “Open & Export” section and then tap on the “Import/Export” option.

And by doing this, you will be able to open the OST file. Not only, you can open the OST file, but also you can also import and export those files in Outlook.