If you’re a user of Outlook you may encounter the following error message on the rarest of occasions when attempting to open the application:
The file <OST file location> is in use and could not be accessed. Close any application that is using this file, and then try again.
This was after I had closed Microsoft Outlook 2013 which was mostly working fine apart from a Gmail account that had stopped working. I even checked the process list in Task Manager to see if outlook.exe was stuck but it wasn’t there.
One thing to try is closing applications that also integrate with Outlook – this may include apps such as Skype or Lync (which was the culprit in my particular case). Make sure your close the app(s) right down so make sure you check the system tray for hidden icons to make sure they are properly closed.
Once done, you should be able to fire up Outlook then your other apps and get on with it 🙂