How to Fix Outlook “OST File in Use Cannot Be Accessed” Error

OST file is in use and cannot be accessed message in Outlook happens when the OST file is locked, corrupted, or is held up by a different program. It can be fixed either by shutting down contradictory applications, by disabling Cached Exchange Mode, or by repairing the file. To provide a stable and legitimate solution, the Aryson OST Recovery Tool will fix any unavailable OST files, preserve all the mailbox information, and reclaim the entire Outlook functionality in a fast and safe manner. Proceed with this blog to Fix “OST File is in use and cannot be accessed” Error: Download Now   Purchase Now

What is the Outlook OST file in use error?

The error of Outlook, which states that the OST file is in use and can not be accessed normally, happens when the Offline Storage Table (OST) file gets locked or unreadable. This issue prevents the opening or synchronizing of emails in Outlook and, therefore, disrupts regular work since the file contains a local copy of your mailbox, which you can use when you are not online.

Common Causes of the Error

• Background programs: There are times when Outlook is not able to access the OST file since the file is already in use by another application in the background.
• Corruption of the OST file: When the file is corrupted, this prevents Outlook from reading and opening the file.
• Unexpected Outlook shutdown: In cases where the Outlook file has been prematurely closed, the OST file might be locked, and it becomes difficult to access.
• Synchronization issues: This Outlook error can also be caused by errors during the synchronization process with the mail server.

With the awareness of these potential causes, you will be able to find the specific cause of the problem and choose the best remedy to address it.

How to Fix “OST File is in use and cannot be accessed” Error

The error message states that Outlook cannot read the OST file as it is used by another process. In some cases, a reboot can fix the problem, however, when that fails, use the following ways to OST file in use error in Outlook:

Method 1: Quit Outlook and the Processes.

1. Close Outlook and open Task Manager (Ctrl + Shift + Esc).
2. On the Process tab, look for Outlook, Skype for Business (LYNC), Communicator, or UCMAPI.
3. End these tasks one by one.
4. Restart Outlook and verify whether or not the problem has been solved.

Method 2: Turn off Security Programs for Outlook OST file repair.

Proceed with these steps too. May be it can be helpful to Fix “OST File is in use and cannot be accessed” Error:

1. The OST file can be locked by antivirus or Firewall software.
2. Turn them off and restart Outlook.
3. In case Outlook is running well, then add Outlook and the OST file as exceptions to your security tool.

Method 3: Check Account settings.

1. Incorrect DNS, port, or proxy configurations can cause errors.
2. To set up an account in Outlook, use File Account Settings Account Settings.
3. Choose your account – Next to Change – Next to More Settings – Advanced.

Option 4: Turn off Problematic Add-ins

Also, you should find the OST file locked by another process. Then, turn off problematic Add-ins with these steps:

1. Boot Outlook into Safe Mode (Windows + R – outlook /safe).
2. In the case that Outlook starts correctly, turn off add-ins:
3. Go to File > Options > Add-ins.
4. In Manage, choose COM Add-ins and then go.
5. Select all add-ins and restart Outlook.
6. Enable the add-ins one at a time to locate the buggy one and delete it forever.

Method 5: Disable Cached Exchange Mode.

Cached Exchange Mode stores mailbox information on the local disk drive, and this could lead to conflict. Here are the steps to fix the Outlook OST file is inaccessible:

1. Access Control Panel, Mail, E-mail Accounts.
2. Choose your account – click on Change.
3. Then click No to Use Cached Exchange Mode and restart Outlook.
4. When the error is deleted, this means that there is a problem with the OST file.

Method 6: Rebuild the OST File

In case of corruption of the OST, recreate it: Follow the given steps to resolve the OST file access error:

1. Open Look and then navigate to the OST file location.
2. Change the extension of the OST file to a .bak file (e.g, a file with the name of an e-mail address, such as abcxyz.com.ost.bak).
3. Restart Outlook, and a new OST file will be generated and synchronized with the server.

Recover the OST files Before Conversion

Along with several reasons, one reason can be your corrupted outlook data file. So all you need to do is recover those OST files first. For ease of the user, we are here with the Aryson OST Recovery tool which will help you restore the OST file with ease. Download the software and get your OST file backup within a few clicks. There is no risk of data loss during the recovery process. When you recover the OST file then move to the next section.

Method 7: Convert OST File to Repair the OST file in Outlook

Sometimes, users get into trouble with corrupted OST files or struggle to move their information between platforms. Under these circumstances, the Aryson OST to PST Converter is the solution. This software has an elaborate preview panel that allows you to preview all the mailbox contents before actual conversion. In addition, it offers the possibility to export only specified folders or emails, which saves time and storage. Also, it will eliminate similar items to maintain your backup clean and tidy. On top of that, its batch processing ability enables you to work with multiple files of OST simultaneously without compromising the processing speed or data quality.

You simply have to take the following simple steps to make the conversion process easier:

1. To start with, download the Aryson OST to PST Converter on your computer.
2. Then, open the program and press Select File to select your OST files.
3. Then, preview the items of the mailbox, like emails, contacts, and calendars, in the preview panel to verify their accuracy.
4. Then you have to select Save As, and the preferred format is PST.
5. Explore and specify the destination folder in which you wish to save the converted files.
6. Lastly, press the Convert button and locate your PST files at the location.

Conclusion

The error message of the inability to operate the OST file, which is in use and is not accessible, can stop Outlook and deny access to valuable email. The manual approach to it will not work, particularly when dealing with large or corrupt OST files. The Aryson OST to PST Converter is a safe solution to fix “OST File is in use and cannot be accessed” Error. It restores all mailbox information, eliminates duplicates, and changes OST files to PST and other formats with complete accuracy. Users will be able to gain full access to Outlook, secure their email, and clean their mailbox effectively without losing any data.

Frequently Asked Questions

About The Author:

Rohan Wiese

Rohan Wiese is a Technical Content Writer at Aryson Technologies, specializing in databases, e-mail recovery, and e-mail migration solutions. He enjoys conducting research and generating information that assists database administrators, businesses, and novices in resolving issues with MS SQL Server, MySQL databases, Cloud Computing, and Microsoft Exchange.

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