This is my Stacktrace:
FATAL EXCEPTION: main java.lang.NullPointerException at com.example.test.fragments.LoadingFragment$1.run(LoadingFragment.java:66) at a
CASE: When you need to call Fragment(Child fragment) from another Fragment(Parent Fragment)
always use getChildFragmentManager() instead of getFragmentManager() inside your Parent Fragment.
getChildFragmentManager()
getFragmentManager()