Outlook 2010 no longer runs. When I open Outlook, I get three error messages, then it closes down an

Not open for further replies.


Error 1: The file ExSec32.dll is incompatible with Microsoft Outlook. Install Outlook again.

Error 2: Either there is no default mail client or the current mail client cannot fulfill the messaging request. Please run Microsoft Office Outlook and set it as the default mail client.

Error 3: Cannot start Microsoft Outlook. Cannot open the Outlook window. The set of folders cannot be opened. 'Microsoft Outlook' exited without properly closing your Outlook data file 'C:\Users\Brandan\Documents\Outlook\Outlook.pst'. 'Microsoft Outlook' must be restarted. If this error message recurs, contact support for 'Microsoft Outlook' for assistance.

-----Outlook is my default and only mail client. I've ran fine for years with Outlook 2003. I purchased Office 2010 Professional Plus (with Outlook) and have intermittent problems with Outlook 2010 since. Please help.

Diane Poremsky

Senior Member
Outlook version
Outlook 2016 32 bit
Email Account
Office 365 Exchange
Not open for further replies.