Test case 1:

public class OuterClass {
    int field;

    public static void main(String[] args) {
        new OuterClass().new InnerClass().method();
    }
    
    class InnerClass {
        
        void method() {
            System.out.println(field);
        }
        
    }
}

Test case 2:

public class OuterClass {
    static int field;

    public static void main(String[] args) {
        new StaticInnerClass().method();
    }
    
    static class StaticInnerClass {
        
        void method() {
            System.out.println(field);
        }
        
    }
}

Steps to reproduce:
1. Put a breakpoint on the System.out.println() statement in one of the test-cases above.
2. Debug the file and wait till it hits the breakpoint.
3. Add "field" watch.
4. Attempt to change the value of the "field" watch.
   => The value is not changed and a warning dialog is shown.
   The dialog says "Cannot set value to 'field', unknown variable.".