Combat engineer does not provide benefits

[Kathi51!]

Dear All,

I am having trouble with the combat engineer benefits.

Having tried using the engineer I get as far as the informational window telling me that I can use the "pop up window" to choose the unit to which I wish to designate the benefit.

Then nada - no window. I´ve tried everything I can think of ....

A turn back it still worked, but I can´t recall how.

Can anyone help. I´m using two monitors.

Thanks