Outlook fails to open with error: 'Microsoft Outlook' exited without properly closing your Outlook data file

Question

After shutting down Outlook forcefully and trying to restart it, the following error is displayed:

'Microsoft Outlook' exited without properly closing your Outlook data file. 'Microsoft Outlook' must be restarted. If this error message recurs, contact support for assistance.

Outlook then exits.

I'm not on a beta version.

Answer 1

• Run Process Explorer and choose "Find Handle or DLL" from the Find menu.
• Search for '.ost'. This will display all open handles to your Outlook data file.
• Choose to close all handles to your .ost file
• Start Outlook again
• optionally - run C:\Program Files (x86)\Microsoft Office\Office14\SCANPST.EXE

Answer 2

I've found that for me this occurs because Outlook crashed for some reason but the Lync 2010 client still has a handle to the .ost file. Exiting Lync completely allows Outlook to restart.