[Android] providerList() returns NULL list

[libplugins_position_qtposition_android_armeabi-v7a.so] _JNIEnv::GetIntArrayElements(_jintArray*, unsigned char*)

This a method "providerList" into QtPositioning.java at "return retList;" (NULL)

static private int[] providerList()
{
    if (locationManager == null) {
        Log.w(TAG, "No locationManager available in QtPositioning");
        return new int[0];
    }
    List<String> providers = locationManager.getProviders(true);
    int retList[] = new int[providers.size()];
    for (int i = 0; i < providers.size();  i++) {
        if (providers.get(i).equals(LocationManager.GPS_PROVIDER)) {
            //must be in sync with AndroidPositioning::PositionProvider::PROVIDER_GPS
            retList[i] = 0;
        } else if (providers.get(i).equals(LocationManager.NETWORK_PROVIDER)) {
            //must be in sync with AndroidPositioning::PositionProvider::PROVIDER_NETWORK
            retList[i] = 1;
        } else if (providers.get(i).equals(LocationManager.PASSIVE_PROVIDER)) {
            //must be in sync with AndroidPositioning::PositionProvider::PROVIDER_PASSIVE
            retList[i] = 2;
        } else {
            retList[i] = -1;
        }
    }
    return retList;
}

Android error: JNI DETECTED ERROR IN APPLICATION: java_array == null

backtrace:

  #00  pc 0x0000000000064f9c  /apex/com.android.runtime/lib/bionic/libc.so (abort+172)
  #01  pc 0x0000000000034499  /apex/com.android.art/lib/libc++.so (abort_message+92)
  #02  pc 0x00000000000345ed  /apex/com.android.art/lib/libc++.so (demangling_terminate_handler() (.__uniq.205383134706309982814331919004001075825)+120)
  #03  pc 0x0000000000034df7  /apex/com.android.art/lib/libc++.so (std::__terminate(void ())+2)
  #04  pc 0x00000000000346f5  /apex/com.android.art/lib/libc++.so (_cxxabiv1::failed_throw(cxxabiv1::cxa_exception*) (._uniq.322141405278763512308061072235179479160)+12)
  #05  pc 0x000000000004adc1  /apex/com.android.art/lib/libc++.so (__cxa_throw+72)
  #06  pc 0x0000000000047def  /apex/com.android.art/lib/libc++.so (operator new(unsigned int)+54)
  #07  pc 0x000000000004e533  /apex/com.android.art/lib/libc++.so (std::_1::basic_string<char, std::1::char_traits<char>, std::1::allocator<char> >::_grow_by_and_replace(unsigned int, unsigned int, unsigned int, unsigned int, unsigned int, unsigned int, char const*)+86)
  #08  pc 0x000000000004a05d  /apex/com.android.art/lib/libc++.so (std::_1::basic_string<char, std::1::char_traits<char>, std::_1::allocator<char> >::append(char const*, unsigned int)+60)
  #09  pc 0x000000000000d5bd  /apex/com.android.art/lib/libbase.so (android::base::ReadFdToString(android::base::borrowed_fd, std::_1::basic_string<char, std::1::char_traits<char>, std::_1::allocator<char> >*)+152)
  #10  pc 0x000000000000d65f  /apex/com.android.art/lib/libbase.so (android::base::ReadFileToString(std::_1::basic_string<char, std::1::char_traits<char>, std::1::allocator<char> > const&, std::1::basic_string<char, std::1::char_traits<char>, std::_1::allocator<char> >*, bool)+106)
  #11  pc 0x00000000000439bb  /apex/com.android.art/lib/libunwindstack.so (unwindstack::Maps::Parse()+66)
  #12  pc 0x0000000000009af3  /apex/com.android.art/lib/libbacktrace.so (UnwindStackMap::Build()+758)
  #13  pc 0x000000000000a055  /apex/com.android.art/lib/libbacktrace.so (BacktraceMap::Create(int, bool)+124)
  #14  pc 0x000000000025ed07  /apex/com.android.art/lib/libart.so (art::ThreadList::Dump(std::_1::basic_ostream<char, std::_1::char_traits<char> >&, bool)+166)
  #15  pc 0x00000000005078b5  /apex/com.android.art/lib/libart.so (art::AbortState::Dump(std::_1::basic_ostream<char, std::_1::char_traits<char> >&) const+136)
  #16  pc 0x0000000000501a3f  /apex/com.android.art/lib/libart.so (art::Runtime::Abort(char const*)+1342)
  #17  pc 0x000000000000fc99  /apex/com.android.art/lib/libbase.so (android::base::SetAborter(std::_1::function<void (char const*)>&&)::$_3::_invoke(char const*)+48)
  #18  pc 0x000000000000f55b  /apex/com.android.art/lib/libbase.so (android::base::LogMessage::~LogMessage()+226)
  #19  pc 0x000000000024bb4f  /apex/com.android.art/lib/libart.so (art::JavaVMExt::JniAbort(char const*, char const*)+2866)
  #20  pc 0x000000000047e8b7  /apex/com.android.art/lib/libart.so (int* art::JNI<false>::GetPrimitiveArray<_jintArray*, int, art::mirror::PrimitiveArray<int> >(_JNIEnv*, _jintArray*, unsigned char*)+614)
  #21  pc 0x00000000000089d0  /data/app/~~damsLktl-3KFzjMsCuNskQ==/rjr.heron.android-_DmG-wXCmg9GuwBCYlV1bQ==/lib/arm/libplugins_position_qtposition_android_armeabi-v7a.so (_JNIEnv::GetIntArrayElements(_jintArray*, unsigned char*))