When debugging stepping over each line does work.

Stepping into a function located in another file debugger displays: Source not found.

Also displays option for Edit Source Lookup Path... but the correct package is listed there.
(Also tried pointing with the directory path.)

No other breakpoints set, as is a common solution.

Any point in the right direction is helpful.

Thank You.

Thread[main] in the debugger window:

Thread [main] (Suspended)   
    ClassNotFoundException(Throwable).<init>(String, Throwable) line: 217   
    ClassNotFoundException(Exception).<init>(String, Throwable) line: not available 
    ClassNotFoundException.<init>(String) line: not available   
    URLClassLoader$1.run() line: not available  
    AccessController.doPrivileged(PrivilegedExceptionAction<T>, AccessControlContext) line: not available [native method]   
    Launcher$ExtClassLoader(URLClassLoader).findClass(String) line: not available   
    Launcher$ExtClassLoader.findClass(String) line: not available   
    Launcher$ExtClassLoader(ClassLoader).loadClass(String, boolean) line: not available 
    Launcher$AppClassLoader(ClassLoader).loadClass(String, boolean) line: not available 
    Launcher$AppClassLoader.loadClass(String, boolean) line: not available  
    Launcher$AppClassLoader(ClassLoader).loadClass(String) line: not available  
    MyMain.<init>() line: 24    
    MyMain.main(String[]) line: 36