Kotlin Error: Dagger does not support injection into private fields

Question

I use in kotlin activity ViewPager and I want in Kotlin Fragment use the dagger injection. I have got Error: Dagger does not support injection into private fields. In Java Fragment the dagger injection work. Why can i not inject dagger in kotlin faragment ?

in my kotlin activity

mPagerAdapter = object : FragmentPagerAdapter(supportFragmentManager) {

        private val mFragments = arrayOf(KotlinFragment(), JavaFragment())
        private val mFragmentNames = arrayOf(getString(R.string.cashdocuments), getString(R.string.action_absmysql))

        override fun getItem(position: Int): Fragment {
            return mFragments[position]
        }

        override fun getCount(): Int {
            return mFragments.size
        }

        override fun getPageTitle(position: Int): CharSequence {
            return mFragmentNames[position]
        }
    }

my kotlin fragment

class KotlinFragment : Fragment()  {


@Inject
internal var mSharedPreferences: SharedPreferences? = null

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)

    (activity.application as SamfantozziApp).dgaeacomponent().inject(this)

}

override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?,
                          savedInstanceState: Bundle?): View? {
    super.onCreateView(inflater, container, savedInstanceState)
    val rootView = inflater!!.inflate(R.layout.activity_absserver, container, false)

    return rootView
}

}

messages gradle build

Answer 1

Accidentally I came across to my own answer and have to confess, that in fact it isn't working (at least for my use-case). Please consider Avilio's answer which worked for me also: substitute internal with lateinit.

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Old answer

Remove internal modifier. Dagger needs at least package-private access in order to access annotated field. In Kotlin internal modifier is not a substitution for Java's package-private access modifier.

For detailed explanation of differences between modifiers in Java and Kotlin refer to Fragmented podcast's episode #101 - "Learning Kotlin – visibility modifiers, internal modifier, modules", as well as the official docs.