我正在使用这段代码来解析一个json文件，并更改我构建的de app中的一些项：

fun fetchJson() {

        if (isNetworkAvailable()) {

            val request = Request.Builder().url(stationAPPJsonURL).build()

            client.newCall(request).enqueue(object : Callback {

                override fun onResponse(call: Call, response: Response) {

                    val body = response.body?.string()

                    val gson = GsonBuilder().create()

                    try {

                        val stationAPP = gson.fromJson(body, StationAPP::class.java)

                        //ACTIE
                        actie_zichtbaar = stationAPP.actie_zichtbaar
                        actie_img = stationAPP.actie_img
                        actie_url = stationAPP.actie_url

... I left out some code

                    catch (error: JsonParseException) {

                        runOnUiThread {

                            val toast = Toast.makeText(applicationContext, "Problem loading JSON.\nFunctionality may be limited for a while.", Toast.LENGTH_SHORT)

                            val view = toast.view!!.findViewById<TextView>(android.R.id.message)
                            toast?.let { view.gravity = Gravity.CENTER }
                            toast.setGravity(Gravity.CENTER, 0, 0)
                            toast.show()

                        }

                    }

               }

                override fun onFailure(call: Call, e: IOException) {
                runOnUiThread {

                    val toast = Toast.makeText(applicationContext, "Problem loading JSON.\nFunctionality may be limited for a while.", Toast.LENGTH_SHORT)

                    val view = toast.view!!.findViewById<TextView>(android.R.id.message)
                    view?.let { view.gravity = Gravity.CENTER }
                    toast.setGravity(Gravity.CENTER, 0, 0)
                    toast.show() --> line 1390!!

                }

            }

         }

  }

我在Google Play控制台的日志中看到这部分代码有时会崩溃（4%）。我不知道为什么？我在几台设备上测试过，没有任何错误。
谁能帮我一下？
是否可能：瓦尔stationAPP = gson.fromJson（body，StationAPP：：class.java）没有抛出异常，但不知何故，加载的json文件中有一些错误？因此，有些项为空？
谢谢你的帮助;）
更新：这是它产生的错误：

Exception java.lang.NullPointerException:
  at com.familiekoning.grolloo.MainActivity$fetchJson$1.onFailure$lambda-10 (MainActivity.kt:1390)
  at com.familiekoning.grolloo.MainActivity$fetchJson$1.$r8$lambda$lczurdfMtnZdFDn9iwHvPqw9_Pg
  at com.familiekoning.grolloo.MainActivity$fetchJson$1$$ExternalSyntheticLambda8.run
  at android.os.Handler.handleCallback (Handler.java:938)
  at android.os.Handler.dispatchMessage (Handler.java:99)
  at android.os.Looper.loop (Looper.java:250)
  at android.app.ActivityThread.main (ActivityThread.java:7806)
  at java.lang.reflect.Method.invoke
  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run (RuntimeInit.java:592)
  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:958)