Cannot change predefined symbol
The compiler detected an attempt to use the #define or #undef directive on a symbol already defined in Java. This error occurs when a symbol such as true or false, which are already defined for conditional compilation, is redefined using the #define or #undef conditional compilation directives. Remove or change the #define or #undef directives specified in the error and compile again.
The following example illustrates this error:
#undef false //error: cannot undefine the 'false' symbol
#define true //error: cannot define the predefined 'true' symbol
public class Simple{
//do something here
}