Buttons are disabled?

[Anonymous]

I opened a new file.

The book I am reading says to click on the Subregion button.

It is grey and disabled.

How can I enable it?

Thank you for your help.

[constantin.stroescu · Accepted solution]

it looks as you have no Toposurface in your Project.

Create ,first , a Toposurface....placing Points - for instance...then the Modify Site  will activate...

[Anonymous]

That worked.  Thank you.