Solution to Fix “default outlook profile.ost is in use and cannot be accessed ” Error

The Microsoft Outlook and Exchange servers are the widely used applications. Most of the users  who work with MS Outlook were familiar with .OST extension.  It is also known as Offline Storage Table used to store your mailbox’s items (Emails, Contacts and Calendars, etc.) when you’re working with Exchange Server and MS Outlook in offline mode.

Sometimes you start getting error “Outlook.ost file is in use and cannot be accessed close any application that is using this file”. Which means the OST file you are trying to open is already used by another program or application. There are a few similar errors which you may notice while accessing the default OST file:

1. .ost file in use error outlook 2010, 2007, 2003
2. outlook 2010 ost file in use and cannot be accessed
3. ost file is in use by another application
4. cannot display the folder the file outlook ost is in use and cannot be accessed
5. default outlook profile.ost is in use and cannot be accessed

Reasons behind The Error “OST is in use and cannot be accessed”!

These errors mainly occur when multiple users or application are trying to use the same OST file. Apart from that, here are some of the common reasons for such queries:

• Due to slow internet connection
• While synchronizing .ost file on the local machine with the Microsoft Exchange server mailbox
• Runtime conflict of certain other programs with the Outlook application
• Attempting to access the same. ost file by multiple users at the same time

Solutions to Fix .ost file in use Error Outlook 2013, 2010, 2007 & 2003

After confirming how to detect the error and finding the reasons behind it, the next step is to try and resolve these issues. For this there are three approaches explained  which will help you to understand how to fix default outlook profile.ost is in use and cannot be accessed error.

Solution-1:  Close MS Outlook and Kill All Outlook Related Processes

This is initial solution may be helpful to fix the above listed errors. Follow the step by step guide to perform the task.

1. In the first step, close your Microsoft Outlook safely.
2. Now Right-click the task bar and select “Task Manager”
3. Choose the “Processes” tab.
4. Search “Communicator“, “Lync“, “ucmapi” or “Outlook“. If you find, then select the “End task” button.

Solution-2:  Disable Cached Exchange Mode

This is another method may help you to solve the issue. In this method you just need to disable cache Exhnage Mode by following below steps:

1. Close the MS Outlook.
2. Open “Control Panel” and choose “Mail“.
3. Select the “Email Accounts” button and choose the “Email” tab.
4. Choose the Email-Id and then click on the “Change“.
5. Uncheck “Use Cached Exchanged Mode“ >> Select “Next” >> “Finish“.

Solution-3: Run ScanOST.exe  Application

This is the last but effective method to fix error “host file is in use cannot be accessed” and make OST file readable.

1. Close the MS Outlook application.
2. Launch ScanOST.exe
3. Choose Mailbox >> Select the ‘Repair Errors‘ >> Click on ‘Begin Scan’.
4. It will take a few minutes to scan hierarchy and fix errors.

Conclusion: In this article three different methods are discussed to fix error “cannot display the folder the file outlook ost is in use and cannot be accessed”. In case above solutions fails to repair and fix these issues, then you use OST to PST conversion solution provided by MailsDaddy . It will fix the ost file is in use by another application error and give you another file with extension .pst which can be directly opened or imported into all editions of Microsoft Outlook.