Adding weight constraint to a control flow

[Jamie_Campbell]

I'm trying to add a weight constraint to a control flow on an Activity Diagram. I can get to the Controlflow Properties screen displaying Guard  and Weight; I can add a guard condition but I cannot type anything into the Weight textbox.
I'm obviously missing something but I don't know what. I've just upgraded to EA10 from EA8 (where I could add a weight!)
Any help gratefully received.

[qwerty]

In EA 9.3.934 it's also not possible to enter something in weight. Though you can place the cursor in that box. Strange. But if in EA 8 this was possible I suspect a bug which had been introduced a while ago.

q.