Unable to Expand Folder Error in Outlook 2010 OST

Resolve Unable to Expand Folder in OST

As we all known Outlook 2010 is among the most stable and reliable email client application used by millions of people around the Globe. People make use of this utility to communicate with their employees in an organization (OR) use them for their personal needs. Outlook 2010 application is widely used when compared to other email client utilities because it helps you continue your work on Outlook even if there is zero internet connectivity; if you are wondering, how? Then the answer is with the help of OST file.

OST files are Offline Storage Tables, which are generally used to save vital attributes of Outlook application; this database file gives you the freedom to work on Outlook 2010 application offline. Nonetheless, similar to other database file Outlook OST files get corrupt and damaged due to numerous reasons. More often than not, Outlook users receive error notification when accessing data from a corrupt OST file and one common error is

Error Name: "Unable to expand the folder. The set of folders could not be opened. Errors could have been detected in the file pqr.ost. Quit all mail-enabled applications, and then use the Inbox Repair Tool."

There are mainly three major causes, due to which you receive the above stated error notification. They include incorrect mail profile, Incorrect Outlook email account settings and Corrupt Outlook OST file.


There are few manual ways through which you can overcome “unable to expand the folder” error message. Just follow these manual techniques and see whether it helps

For Incorrect Mail Profile:

  • The only and best option to eliminate incorrect mail profile problem is by deleting the old profile and recreating it.

    Recreation of mail profile is as follows, Close Microsoft Outlook --> Go to Control Panel --> Double-click Mail --> Select “Show Profiles” from Mail Setup dialog box --> From the displayed list, remove the incorrect profile --> Later, create a new profile by clicking add email accounts based on your server settings --> Restart Outlook

For Incorrect Email Settings:

  • To correct your Outlook 2010 email settings, Open Outlook go to Account settings and see whether your emails address, server settings, account information are correct. If not make the necessary changes and restart Outlook.

Hopefully, these two methods will help your resolve the problem. However, if the error pops up even after performing the above motioned techniques; then this could be as a result of OST file corruption. Hence, you need to repair the OST file to sort out the problem.

Fixing Outlook 2010 OST file:

  • Manual Way: Make use of “Scanost.exe” utility to repairs errors in OST file, the procedure is as follows

    Close Microsoft Outlook --> Run Scanost.exe by double clicking the exe file. (Location of Scanost.exe: drive: \Program Files\Microsoft Office\OFFICE12) --> Click Connect if you are prompted to Connect or Work Offline --> Tick the checkbox which says “Repair Errors” and then click on “Begin Scan”.

If the above listed manual methods doesn't work out and even this OST Integrity tool is giving no results, then you have no other option but to use Remo Repair software to resolve any errors associated with your Outlook 2010 OST file.

  • Use Remo Repair OST to PST Coverter utility: One of the best ways to fix Outlook OST error “unable to expand the folder” error is with the help of Remo Repair software. This tool helps you in fixing your severely corrupt or damaged OST file in a matter of minutes; You can make use of this utility to fix password protected, encrypted and large sized OST files. Moreover, supports fixing of OST file created on all Microsoft Exchange versions including 5.0, 5.5, 2000, 2003, 2007 and 2010 on all major Windows operating systems (XP / Vista / 7 / 8).



Follow this process for fix unable to expand folder error in Outlook 2010:

Step 1: Download and install Remo OST to PST Converter software to convert OST to PST Outlook 2003. Run the application by double clicking on desktop shortcut or via start menu. The main screen shows two options, "Open OST File” and “Find OST File”. Make use of "Open OST File" option to choose your OST file if you know its exact location or use “Find OST File” option to search for your OST file.

Unable to Expand Folder Error in OST Outlook 2010 - Main Screen

Figure A: Main Screen

Step 2: After this, use browse button to locate the OST file which needs to be repaired and click on next to start the repair process. This tool will repair your corrupt OST file within few minutes. It even safely convert the OST to PST.

Unable to Expand Folder in Outlook 2010 OST - Browse OST File

Figure B: Browse OST File