VASST Ultimate S Pro Quad-cam: three video tracks but empty dropdown boxes

Hi.

I'm trying to use VUSP 4 with Veg 9.0e for a multicam edit
after almost a year since the last time I used it so,
probably it's just me.

In my project I have three video tracks all named
but they apper only in the first of the dropdown boxes
of the four monitors in the Quad-cam page of US pro.

The Tally dropdown box is empty too.

If I use the "Load cameras" button nothing happens.
If I use the "Apply" button I get the error: "Object reference
not set to an instance of an object".

Is there a way to reset Quad-cam to blank? In the manual I can't find a way to do it.

Thanks.

Thank you, John.

I opened a new instance of Vegas and copied there
all the tracks and the markers. After I named the tracks
all the dropdown boxes got populated (doesn't sound as
a very good english...) and continued to work from there.

One thing is that, even if I selected a red PAL tally
without checking the "use safe area" box, every time
I switch camera I see an overlay that shows the safe area.
When I update the tally the overlay changes to the one
I chose but at the next camera switch I'm still getting
the safe area overlay: anything I can do?

Thanks.

US 4.1.4