Fix errors could have been detected in OST file in MS Outlook
OST file is the core of your Outlook as it saves all the work which has been done offline. Once the connection with Exchange Server is established, OST file gets synchronized automatically and all the work is updated. Any corruption to such vital file could result in various problems when you work on Outlook. When you try to open or synchronize an offline folder OST file which is corrupted or damaged the following error message is generated:
"Unable to expand the folder. The set of folders could not be opened. Errors could have been detected in xxx.ost file. Quit all mail-enabled applications, and then use the Inbox Repair Tool."
To deal with such issues, Microsoft has provided an inbuilt utility Inbox Repair Tool (scanost.exe) which tries to repair corrupted OST files. In case, scanost.exe fails to repair the file, follow the particular steps given below:
- Clear offline data: To clear the offline data, go to offline data folder and then click on its ‘Properties’. Choose the option of ‘Clear offline data’ which is available there and then click on OK. Update Folders after deleting offline data.
- Create a new OST file: Search for the OST file which is creating problem. Now use third party tool to repair the corrupted OST file and save it in PST format. Take backup of your original OST file. Now delete or rename the original OST file. Send/Receive mail through Exchange mailbox, which will let Outlook to create new OST file which will get synchronized with the mailbox automatically. Copy the content of your old OST file which is now present in PST format to newly created OST file.
- Create a new Outlook profile: In case nothing works out, delete the existing profile which has corrupted OST file from your Outlook account. Create a whole new Outlook profile which will automatically create fresh OST file when you start working on it.