WebApp project on NetBeans shows: "Node.js: Missing node.js sources (in NodeJsWebApplication)"

Question

I installed NetBeans IDE 8.2.
I created a new project:

I keep receiving error:

Node.js: Missing node.js sources (in NodeJsWebApplication)

I pressed on Resolve.. but it opens the Options window and all the settings looks OK:

In the NetBeans forums they wrote that restarting the IDE should solve it but I tried it and it doesn't help.

I have Node.js version v6.11.2 and Express vesrion 4.16.0.

I tried to install npm but in the terminal it writes:

"C:\Program Files\nodejs\npm.cmd" "install"
npm WARN [email protected] No description
npm WARN [email protected] No repository field.
npm WARN [email protected] No license field.
Done.

Answer 1

I needed to download the sources.
Notice on my question picture "Not downloaded".

I pressed the Download.. button and it started to download the sources:

The error disappeared.