Problem material editor

I installed Unreal Engine in my new PC, the latest version (4.17) and one older. I started the program without problems, but when I tried to modify a material, I couldn’t. All parameters are empty or in zero. And I tried to create a new material, neither work.
Who can help me!!

So you create a new material in the content browser, double click it to open its graph and what exactly does not work there?

Is there anything specific in the spaghetti up there that you’re having problems modifying?

the spaghetti is empty always

I do not understand. You either see the nodes or you do not.

Also, in the original post:

And I tried to create a new material,
neither work. Who can help me!!

You cannot create new materials?

yes, the spaghetti is empty always, I try to modify a material that I had in my other pc. I give double click and it appears empty. For example “gold material” I can use it in the principal editor, but I give double click in the material to modify it and the spaghetti appears empty.

No, neither. I cannot modify or create.

Could you elaborate please? What happens exactly if you do the following in the content browser:

Once created, double clicking it should produce this:

I did it:

I tried to put a simple vector of three parameters:

I tried to put some color:

But when I clicked in accept, nothing changes and the same happens with all thing that I’ve put in spaghetti.

I don’t know what’s happening, there should have appeared the color changed, but no.

You need to connect it:

yes, of course that I know that I have to connect the nodes, but nothing happens. Simply the vector doesn’t changes, if I try to change it, It doesn’t change and It’s always in black color. I’m going to reinstall the program.

Judging by the picture you uploaded, you set the colour to black. The right hand side slider is still at the very bottom. The RGB reads 0,0,0.