exception in thread 'main' java.lang.NoClassDefFoundError:

Question

The following program is throwing error:

public class HelloWorld {
    public static void main(String args[]) {
        System.out.println(\"Hello World!\");         


        

Answer 1

I had the same problem, and stumbled onto a solution with 'Build Main Project F11'. The ide brought up an "option" that I might want to uncheck 'Compile on Save' in the Build > Compiling portion of the Project configuration dialog. Unchecking 'Complile on Save' and then doing the usual (for me) 'Clean and Build' did the trick for me.