UML Activity Object in State - Can't change state box

[matthew.whetton]

Hi all,

I've just started using Visio fopr my UML diagrams and am trying to
complete an activity diagram, which will show the state of an object
all the way through a process. Problem is when I add an object in
state box to my diagram the State option is always greyed out.

How can I change this?

Thanks for your help

Matt