OST file i.e. also known as Offline Storage file/table is being created when Outlook is configured to work with IMAP or Exchange account. This OST file enables us to work in cached/offline mode. When we work offline this OST file is being used & gets updated and later being synchronized with Exchange Server to update itself and the online mailbox. Sometimes this OST file becomes inaccessible due to some issues or corruption in such a case you become unable to access the OST file components.
Ok, let’s consider a practical situation, suppose you are using Outlook and suddenly a message pops up as below:
“The file OST_File_Path\outlook.ost is already in use by the maximum number of applications. Close some of the applications, and then try again.”
This is one of the most common error message that Outlook users face regularly.
Why this error?
You get this error because either you are trying to access some corrupt OST file. Or your OST file is being used by so many applications and due to which it becomes irresponsive and Outlook is not able to communicate with it.
How to Resolve it?
If the error is due to the use of OST file by various applications, then proper restarting of the system will resolve the issue.
If the reason behind the error is not resolved after restarting the system, then the corrupt OST file is the reason behind this error. To recover OST file you have two options.
Ok, let’s consider a practical situation, suppose you are using Outlook and suddenly a message pops up as below:
“The file OST_File_Path\outlook.ost is already in use by the maximum number of applications. Close some of the applications, and then try again.”
This is one of the most common error message that Outlook users face regularly.
Why this error?
You get this error because either you are trying to access some corrupt OST file. Or your OST file is being used by so many applications and due to which it becomes irresponsive and Outlook is not able to communicate with it.
How to Resolve it?
If the error is due to the use of OST file by various applications, then proper restarting of the system will resolve the issue.
If the reason behind the error is not resolved after restarting the system, then the corrupt OST file is the reason behind this error. To recover OST file you have two options.
- You can recreate OST file. To recreate OST file backup OST file by renaming OST file. A new OST file will be automatically created with all current online mailbox content, when you get connected with the Exchange Server.
- Using this option you can recover the current online mailbox component, but what in case you have some important work done in the OST file and that is not synchronized with the Exchange Server. In that case you need to recover the OST file. Outlook comes with built-in utility named scanost.exe and scanpst.exe that can be used to repair/recover the OST file. Search your system to find both files and then use them to recover/repair corrupt OST file.