I get an errror "the form cannot be displayed" in Calendar

[Guest]

I can open existing Calendar appointments but something happened where when I
attempt to open a new calendar appointment I get an error. The error is "the
form required to view this message cannot be displayed. Contact your
administrator.

 

[Brian Tillman]

I can open existing Calendar appointments but something happened
where when I attempt to open a new calendar appointment I get an
error. The error is "the form required to view this message cannot be
displayed. Contact your administrator.

Clear the forms cache.
http://www.howto-outlook.com/downloads/clearformscache.htm