How to Fix Outlook Cannot Open OST File Error?

“My Outlook OST is displaying an error message whenever I try to access data from it. The error message reads like this “Outlook cannot open OST file because the file xxx.ost is not an offline folder file”. Can anyone tell me what this error message indicates? I have tried fixing the error using Inbox Repair tool, but this utility failed to mend OST file error. Is there any alternate way to get rid of error message and make my OST file work fine?”

The above given scenario is one of the example that many Outlook users often face. If you have got same error and cannot open your Offline folder (.ost) file then it clearly shows that your OST file is corrupted. Therefore, to fix this issue you should first convert OST file to PST file using the manual way provided by Microsoft. Go according to the steps detailed below to convert OST file to PST:

  • First of all open Outlook and then click on “File” option
  • Choose “Import and Export” from the list
  • Select "Export to a file" from the list of actions and press "Next"
  • Choose "Personal Folder File (.pst)" as the file type and press "Next" again
  • Click "Personal Folders” and then check the box "Include subfolders". This will export everything from OST file to a PST file
  • Now choose appropriate categories in the list if you want to export only certain data such as notes and click "Next"
  • Press the "Browse" button and select the location where you want to save the new PST file and press "OK"
  • At last click on "Finish" button to begin converting the OST data to a new PST file

Soon after using this procedure, OST file will be successfully converted to PST file and you can view emails, calendars, tasks, notes and other attributes. But this method sometimes fails to convert when the size of OST file is very big or if OST file is severely corrupted. Under such circumstances, you should make use of reliable OST to PST Convertor software to resolve Outlook cannot open OST file error and at the same time convert OST file to PST file.

OST to PST Convertor software

Yodot OST to PST Converter tool is best option in case you want to convert inaccessible OST to PST file in efficient way. This software can help you to resolve ‘Outlook cannot open OST file’ error and assists you in converting corrupt OST file to a healthy PST file. The conversion procedure is very simple and you can recover attributes like emails, contacts, calendar, tasks and other attributes from OST file after converting OST file to PST file. This utility supports the conversion of OST file created on Microsoft Exchange servers 5.0, 5.5, 2000, 2003, 2007, and 2010 on Windows operating systems. To get detailed information about the features and conversion process just download its demo version and check its efficiency.

Procedure to convert OST file to PST to fix outlook cannot open OST file error:

  • Download and install Yodot OST to PST Converter software on your Windows computer
  • Launch the software and then follow the steps mentioned on the screen
  • The main screen displays two options, "Open OST File” and “Find OST File”
  • Select "Open OST File" if you know the location of OST on your computer or select "Find OST File" if you are not aware of OST file location
  • Next window allows you to browse for the destination path to store the converted OST file data
  • Click on “Convert” button to begin conversion process
  • After conversion, you will receive a confirmation message that “OST file conversion completed"

Suggestions to Consider:

  • Make sure that you close OST file properly after completion of your work, as it might lead to corruption when closed inappropriately
  • Keep on deleting unwanted files from OST because chances of corruption is high when OST file size increases