Android studio unfortunately app has stopped

See more:

Java

Im not sure whether this is the part that cause the app to stop but i cant identify which part of it caused the error

What I have tried:

@Override
   public void onFileClicked(File file) {
       if (file.isDirectory()) {
           Bundle bundle = new Bundle();
           bundle.putString("path", file.getAbsolutePath());
           InternalFragment internalFragment = new InternalFragment();
           internalFragment.setArguments(bundle);
           getChildFragmentManager().beginTransaction().replace(R.id.fragment_container, internalFragment).addToBackStack(null).commit();
       }else{
           try {
               FileOpener.openFile(getContext(), file);
           } catch (IOException e) {
               e.printStackTrace();
           }
       }
   }