Outlook Contact Task Button error

I need help. I use outlook extensively and I was trying to view my activities
under a contact and I wanted to add a field to my view to allow me to see the
date of the activity and when I tried to add "sent" an error appeared and now
I cannot view my activities. Here is the error I get when I try to access an
activity of a contact. "Outlook cannot display this view. Could not complete
the operation one or more parameter values are not valid" How do I correct
this? Do I need to re enstall outlook?