Hello CRM Gurus, One of my CRM user is getting this error message (Image Below) continuously.

I was looking for Error help but could not find much information on this error.
User is using a shortcut of Activities entity in the Favorite Folders area of Outlook 2007. It was working absolutely fine, all of a sudden on the click of this particular short-cut
is popping up this error "Microsoft Dynamics CRM has encountered a problem and needs to close. We are Sorry for the inconvenience."
Other short-cuts for Accounts and Contacts are still working fine.
Also, he is getting the same error when he navigates through Outlook > CRM Tenant Name>Workplace>My work> Activities.
But this user is able to access Activities from IE.
Is there any way to troubleshoot this error, so annoying.I can not reproduce the error in my machine.
IS THIS ERROR caused because of OUTLOOK or DYNAMICS CRM 2011.
Please point me to some blogs and links or suggest the best approach.
Thanks everyone.
Any help will be much appreciated.
Puneet Joshi - Dynamics CRM Developer