This compilation unit is not on the build path of a Java project

Question

When I try to use ctrl+space this error is shown:

This compilation unit is not on the build path of a Java project.

I see tha

Answer 1

Another alternative to Loganathan Mohanraj's solution (which effectively does the same, but from the GUI):

1. Right-Click on your project
2. Go to "Properties"
3. Choose "Project Natures"
4. Click on "Add"
5. Choose "Java"
6. Click "Apply and Close"