Fix “Username.ost is in use and cannot be accessed” Error in Outlook?

The Last night, I was working for quite a while using Outlook using offline mode. It was running very well. But , this morning, whenever I attempted to access the OST file using Outlook the program failed provide an error message saying it was a “username OST is currently in use and cannot be found.” After looking through some discussion forums, we came to this article.

In essence, OST files (cached mode) allow individuals to operate offline. When the system is connected to the internet the necessary changes in the local mailbox as well as within the OST are added to that of the servers mailbox.

However, due to issues related to the OST document and its associated issues, an Outlook user could occasionally experience problems similar to those that were mentioned. In this article we will discuss the possible causes and the solutions to the problem that is causing the OST file isn’t accessible.

Reasons behind the error “username OST is in use and cannot be accessed.”

The problem can occur for various reasons, but it more often occurs when the user is trying to “Start sharing” or “Save and Share” from an MS Office document using functionalities such as MS Word, PowerPoint, Spreadsheet etc. There could be a variety of other possible causes that led to the error, ones like:

• The OST document and the Exchange mailboxes aren’t synced.
• Access to internet is not sufficient.
• Many different programs are at odds with the Outlook application.
• Many users are trying to connect to the same OST document.
• It was not possible to access the OST file was not allowed.
• Without a backup power source the device could suffer unintentionally shutting down of the device.
• The Outlook Add-ins are affected by an issue.

Effective approaches to fixing the “username OST is in use and cannot be accessed” error in MS Outlook

Since you’re proficient and have experience in MS Outlook or Windows Operating Systems If you have the necessary experience, you might be able quickly fix the issue. If you don’t have the skills, we’ve offered solutions for this issue below. Since manual methods do not always cooperate, we’ve suggested an alternative method to solve the issue.

Related Software: How to Convert OST to PST file

Stop this Microsoft Outlook program and all associated tasks

Make sure that all versions of Outlook run on the same computer and that none of the other processes require admin rights for this OST document. It could lead to the OST document being marked as “being being used.” The steps are as the following:

• Close Outlook and then open The Task Manager. You can use the Ctrl, Alt, and buttons together to create keyboard shortcuts, and then select “Task Manager” to close Outlook “Task Manager” option.
• Select “Processes” Click on the “Processes” Tab.

• Look for devices that are labeled “Outlook”, “LYNC”, “Communicator”, or “UCMAPI” in the list.
• Choose these types of mechanisms and then tap on the “End Task” icon individually.

Deactivate the “cached mode”

In essence, the “Cache Exchange Mode” lets Outlook users to carry out their essential work offline. This issue can be solved by partially disabling this feature. Follow the steps below to disable “Cached Exchange Mode.”

• After you have closed your MS Outlook programs, navigate to the “Control Panel” of your device.
• Within the Control Panel Select the Control Panel “Mail,” and a separate screen will be displayed.

• Select “Email Accounts” from the open screen, then “Email.”

• Choose the email account which is connected to Outlook and then press “Change.”

• Then make sure to uncheck “Cached Exchange Mode” and select”Next” and then the “Next” icon, and then select the “Finish” option.

Remove the add-ins that are suspicious

While add-ins are designed to enhance Outlook’s features as well as functions, faulty add-ins could sometimes cause issues, such as the creation of an OST file that’s not accessible.

In the end disabling the add-ins you are having trouble with could fix the issue and enable you to access an Outlook user account and the OST document. To determine if the issue is due to a malfunctioning add-in, run Outlook using “Safe Mode.” Take the steps below:

• Then, you must open your run windows (you can use the windows and R buttons simultaneously to create an keystroke).
• If you see the Run dialog shows then type “Outlook/safe” to the blank field.
• This means that the Outlook will start in safe mode, and you have to determine whether the program is functioning properly or not. If everything is functioning well, it’s likely the error is due to incorrect add-ins.

If the issue has been fixed, restart Outlook in the standard mode and then deactivate the add-ins one by one and keep an eye for any error. This will let you remove the incompatible add-in and maintaining the other add-ins that are not defective.

Try to fix the OST files in your computer

The majority of the time, people have OST files that are damaged and consequently they are able to reproduce the error. When this happens it is recommended to restore the OST documents. To do this, you can utilize Microsoft’s free program “scanOST.exe” as well as any other professional software. If you’re actually recovering OST files, then you can use an alternative third-party OST Recovery tool.

There are two solutions to repair and recover OST files, which are accessible on the internet. In essence, Microsoft’s scanOST is a basic, unadvanced program. This is why you need an alternative OST fix or repair program.