Solved – Outlook OST File Cannot Be Opened in Outlook 2019/2016/2013/

Ritu Roy | data recovery Email Conversion File Recovery File Repair How to's Software Technology | 4 minutes read | Last updated on February 8th, 2023,

“Looking a solution to resolve “Outlook OST file cannot be opened in Outlook? Don’t be panic. In this informative blog, we will try to give a reliable and best solution to the users using which they can easily regain their OST file data in Outlook”.

Microsoft Outlook is a most used email application which offers various benefits to the users. In Outlook, the OST file is used in order to do the daily tasks. Whereas the PST file, one needs not local machine always connect to Server as it permits to work offline and sync with MS Exchange Server to update the changes. The default destination path of the OST file is C: drive/Users/AppData/Local/Microsoft/Outlook.

The Microsoft Outlook .ost file tool gets damaged and corrupted just like any other file. It leads to corruption due to various malware, viruses, and other malware attacks. Due to the corruption, OST data items including emails, contact, calendars, events, tasks, etc. become inaccessible to the users. In such scenarios, numerous errors occur like ‘Default Outlook .ost cannot be opened’. One technique to store mailboxes and avoid any such action is to backup emails at a regular interval, Archive Outlook .ost file to read and access email messages in case of server maintenance or downtime.

Occurs Some Common OST File Errors in Microsoft Outlook

Microsoft Outlook users at ease with the OST file. So, there are risks that they might encounter the error Outlook OST file cannot be opened in Outlook. Some other OST file errors which are very common and are handled by the Outlook users areas:

  • The outlook is not responding
  • Cannot open Outlook Window
  • OST file cannot be opened
  • The default Outlook .ost file us in use and cannot be opened
  • The set of folders cannot be accessed
  • Network failure
  • Malware and Virus Attacks
  • Damaged Offline .ost folder
  • Corruption in the file system

Manual Solution to Fix Default Outlook .ost File cannot be Opened Error

Whatever the reason behind the error cannot open Outlook offline .ost file in Outlook 2019, 2016, 2013, and other versions, there are many reliable and best solutions to troubleshoot the error. Let’s discuss them.

You can fix this OST file problem using manual techniques. For this, first, take a backup of the .ost file. If the trouble continues, you can try to restart the operating system. Here, the free manual solutions for fixing the “Outlook OST file cannot be opened in Outlook” error are explained:

Approach 1. End complete Outlook related procedures

  • Exit the Microsoft Outlook email program
  • Then, right-click on the taskbar menu and then click on ‘Task Manager.
  • Now, go to the processes option
  • In the methods section, look for the processes Communicator, Lync, Outlook, or Ucmapi. If any of these processes are found, choose, and hit on the End process option.

Approach 2. Disable Outlook Cached Exchange Mode

  • End the MS Outlook application and go to ‘Control Panel’.
  • In the Control Panel, tab the Mail option and then opt for Email Accounts.
  • Now, under the Email Accounts, press the Email tab option.
  • After that, tab the Exchange account and then click on Change.
  • Now, uncheck the use Cached Exchange Mode option under offline settings and press the Next to finish the procedure.

Approach 3. Disable the MS Outlook Add-ins

While add-ins are utilized to improve the functionality of Microsoft Outlook, defective add-ins may sometimes make more issues. Therefore, disable the add-ins by launching Outlook in safe mode by just typing Outlook/safe in the Run dialog box. Try “Save and Send” and if it works, a defective add-in is the main reason behind the error. You can also start Outlook in safe mode by following the below-discussed steps:

  • Click on the shortcut icon for Outlook.
  • Then, tap and hold the CTRL key and double-click the application shortcut.
  • Now, press ‘Yes’ once a window prompt shows asking ‘if you want to start the app in safe mode.

Approach 4. Fix OST File with ScanOST.exe

Microsoft allows the users with an inbuilt ‘OST Integrity Checker tool named is ScanOST.exe that helps to repair minor corruptions in OST files. Repairing the Outlook OST file with SacnOST.exe is a smart way to fix the “Outlook OST file cannot be opened in Outlook’ error. Moreover, this Outlook inbuilt utility is available with Outlook 2007 and below version only.

  • Close the MS Outlook and locate to the instructions on your machine where Outlook has been installed. Now, Locate to the ScanOST.exe and double-click to launch it
  • The app will prompt you to choose the OST file for the fix. Select the OST file. If you don’t know its exact destination, you can find it by typing the following in the address: “%LOCALAPPDATA%\Microsoft\Outlook\”
  • Now, choose the wanted mailbox and other options accordingly
  • Finally, choose “Repair Errors” and hit on “Begin Scan” button to automatically check and remove the discrepancies in the OST file

Cons of Manual Solutions

  • The free methods are very lengthy, complex, and time taking process
  • Required some technical knowledge to perform this process
  • It doesn’t ensure data integrity and security.

Reliable Solution – To Fix Outlook OST File cannot be opened in Outlook

If the above-mentioned methods don’t work to resolve the “Outlook OST file cannot be opened in Outlook” error, you can choose for SacnPST.exe utility for this repair error. Moreover, SacnPST.exe works only in case of minor OST files damage and corruption. Therefore, it is always advised to use an automated OST to PST Converter software to recover and fix the corrupted OST file and the data associated with it to PST.