Fix Outlook Error Cannot open your default email folders or items when offline

Fix the Outlook error “Cannot Open Your Default Email Folder or Items When Offline”

While working on Ms Outlook in offline mode message appears on the screen is “Cannot open particular outlook item when offline”, it means the OST file is corrupted or damaged. It makes Outlook file inaccessible because when the Ms Outlook application disconnects from the Ms Exchange Server then the offline Storage Table (OST) allows you to sustain the work in Ms Outlook. You can make changes offline and once the connection is reestablished offline alternations will be automatically synchronized with the mailbox on exchange server. OST  file is duplicate copy of your mailbox which stores on hard drive of your computer. In case Exchange server gets damaged then it will not affect the OST file on hard drive. But sometime you cannot work offline and the massage on screen “Cannot open particular Outlook item when offline” deny to access the file. This is because of OST file corruption. It is similar to damage in other computers.

But since the error may affect outlook service in the long run, it is important resolve it quickly with quick consideration.

Reasons for corruption of OST file:

There are several reasons for OST file corruption and the reasons may be related to hardware, software, or any other.

Hardware Cause:

  • Crashed data storage device
  • Network failure
  • Power failure

Software causes:

  • Damaged offline folder
  • Incorrect file system recovery
  • Virus and other Malicious software
  • Abnormal Outlook Termination
  • Synchronization Error

Effects of OST Corruption

  • Outlook profile and Exchange account associated with that OST file become inaccessible
  • If you try to access the data this message will display on screen

Cannot open your default email folders. The file C:\…..\outlook.ost is not an offline folder file.
Unable to expand the folder. The set of folders could not be opened. Errors could have been detected in the file xxxx.ost. Quit all –enabled applications, and then use the Inbox Repair Tool

“Confront a large number of conflict items”
Cannot open your default Outlook email folder or item when offline.

Repair OST file

An OST file can only be repaired by convert it into PST format. PST file is the proprietary file format used in all the versions of the outlook application.
To Fix the outlook error “cannot open your default Outlook email folder or item when offline”

Method 1:

  • First you delete the corrupted OST and download it again from the Exchange server.
  • If the data that is locally stored but does not exists on Exchange server then you have to export the data to PST and delete the OST file.
  • Create a new OST and import the downloaded PST data in it.

Process is as follows:

  • Click File -> open ->Import ->import from another program
  • Then click Next and choose outlook data file (.pst) from list of options and then click next.
  • Click on Browse to locate PST file being exported.
  • Select do not import duplicates from options and click on Next.
  • Click on Select destination folder and choose the folder in which you want to import data, and click Next.
  • Click Finish.


This tool is available in Outlook 2007 and earlier versions. Process to run this tool is as follows:

  • Close the Ms Outlook and all the programs accessing it.
  • Locate the OST file from directory structure.
  • Click on scanost.exe.
  • In case you set up the outlook profile, choose appropriate profile prompting on the screen.
  • Then tool again prompt you for either connect or work offline. Click on connect.
  • As per your preference selects the appropriate option and click on Repair Error tool.
  • Click begin to start scanning.


It handles minimal intensity corruption in OST files and it cannot resolve major corruption issues.
You have to keep backup of data before using this tool it involves threat and data loss.

Method 3: OST to PST converter

The above both manual procedures are time consuming and do not guarantee for 100% accuracy. You can trust on OST to PST converter. It is the third party software to export OST file to PST in a very less time period.
This tool supports all UNICODE and ANSI OST versions as it is compatible to run on Ms Outlook 2016, 2013, 2010 and all previous versions. Regardless to the cause it resolves all OST file errors. It can handle large OST and convert it into PST, and keep the original data intact.


Now you know all the 3 methods to convert OST into PST. You can use any method to fix the outlook error message.

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