Hi. I think that there is error in task. I did all of it as it should be done, IDEA shows that code is correct but somehow the website shows errors: java.lang.NullPointerException at pl.codegym.task.task08.task0821.Solution.printListLudzi(Solution.java:33) at pl.codegym.task.task08.task0821.Solution.main(Solution.java:13) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) The only thing i did is: Map<String, String> mapa1 = new HashMap<String, String>(); mapa1.put("anna", "mrok"); mapa1.put("baba", "vfdfdf"); mapa1.put("eqwa", "mbuspoa"); mapa1.put("yrasa", "mdksapa"); mapa1.put("bvcsad", "mrok"); mapa1.put("anna", "odsajmdsa"); mapa1.put("ytrfd", "mdsadop"); mapa1.put("vcsa", "mdsmalas"); mapa1.put("ajhgyua", "mrok"); mapa1.put("anna", "vsdsadsa"); I haven't changed any of the code before or after these lines. Please tell me what is wrong. Thanks