Handling Eclipse Project Reference Problems
If NetBeans identifies an Eclipse project reference problem while
processing an Eclipse project, a warning dialog will be displayed
informing the user NetBeans has found an Eclipse Project Reference
problem along with the corrective action. An example of the warning
dialog is shown below.

To resolve Eclipse project reference
problems, go to the NetBeans Project window, right click the project
just imported and select Resolve Reference Problems as shown below.

After selecting the Resolve Reference
Problems, a Resolve Reference Problems wizard is displayed which
identifies what NetBeans has found for Eclipse project reference
problems. An example of this wizard is shown below.

The
NetBeans Resolve Reference Problems wizard describes the Eclipse
project reference problems NetBeans has found with the Eclipse
project along with a suggested solution. To resolve the Eclipse
project reference problem, you simply press the Resolve button.
That's all there is to it! Although the NetBeans Eclipse
Project Importer cannot automatically resolve all problems it has
found with Eclipse projects, it does give you suggested solutions as
to how to resolve the Eclipse project reference problems it has
found.