Nested dynamic forms

[IntegrityFoundation]

Hi, I am using dynamic form widget for nested dynamic form. The scenario is One Pastor has many short term goals and each short term goals has Misssional goals. So I have three tables:

1. Pastor
2. Shorttermgoals

3. Shorttermmissionalgoals actionCreate is implemented well. I have below actionUpdate. When I run it, foll error is displayed.

   Invalid Configuration – yii\base\InvalidConfigException
   The 'model' property must be set and must extend from '\yii\base\Model'.

   public function actionUpdate($id)
   {
   
       $model = $this->findModel($id);
       $modelsShortTerm=$model->shorttermgoals;
       $modelsShortTermMissional = [];
       $oldShortTermMissional = [];
   
       if (!empty($modelsShortTerm)) {
           foreach ($modelsShortTerm as $indexShortTerm => $modelShortTerm) {
               $missional = $modelShortTerm->shorttermmissionalgoals;
               $modelsShortTerm[$indexShortTerm] = $missional;
               $oldShortTermMissional = ArrayHelper::merge(ArrayHelper::index($missional, 'ShortTermMissionalGoalId'), $oldShortTermMissional);
           }
       }
   
       if ($model->load(Yii::$app->request->post())) {
   
           $modelsShortTermMissional = [];
   
       $oldIDs = ArrayHelper::map($modelsShortTerm, 'ShortTermGoalsId', 'ShortTermGoalsId');
   
               $modelsShortTerm = Modelshortterm::createMultiple(Shorttermgoals::classname(), $modelsShortTerm);
   
               Modelshortterm::loadMultiple($modelsShortTerm, Yii::$app->request->post());
   
               $deletedIDs = array_diff($oldIDs, array_filter(ArrayHelper::map($modelsShortTerm, 'ShortTermGoalsId', 'ShortTermGoalsId')));
   
               $valid = $model->validate();
               $valid = Modelshortterm::validateMultiple($modelsShortTerm) && $valid;
   
               $missionalId = [];
               if (isset($_POST['Shorttermmissionalgoals'][0][0])) {
               foreach ($_POST['Shorttermmissionalgoals'] as $indexShortTerm => $missional) {
                   $missionalId = ArrayHelper::merge($missionalId, array_filter(ArrayHelper::getColumn($missional, 'ShortTermMissionalGoalId')));
                   foreach ($missional as $indexMissional => $missional1) {
                       $data['Shorttermmissionalgoals'] = $missional1;
                       $modelShortTermMissional = (isset($missional1['ShortTermMissionalGoalId']) && isset($oldShortTermMissional[$missional1['ShortTermMissionalGoalId']])) ? $oldShortTermMissional[$missional1['ShortTermMissionalGoalId']] : new Shorttermmissionalgoals;
                       $modelShortTermMissional->load($data);
                       $modelsShortTermMissional[$indexShortTerm][$indexMissional] = $modelShortTermMissional;
                       $valid = $modelShortTermMissional->validate();
                   }
               }
           }
   
           $oldMissionalId = ArrayHelper::getColumn($oldShortTermMissional, 'ShortTermMissionalGoalId');
           $deletedMissionalId = array_diff($oldMissionalId, $missionalId);
   
               if ($valid) {
               $transaction = \Yii::$app->db->beginTransaction();
               try {
                   if ($flag = $model->save(false)) {
                       if (! empty($deletedMissionalId)) {
                           Shorttermmissionalgoals::deleteAll(['ShortTermMissionalGoalId' => $deletedMissionalId]);
                       }
                       if (!empty($deletedIDs)) {
                           Modelshortterm::deleteAll(['ShortTermGoalsId' => $deletedIDs]);
                       }
                       foreach ($modelsShortTerm as $indexShortTerm => $modelShortTerm) {
   
                           if ($flag === false) {
                               break;
                           }
   
                           $modelShortTerm->PastorId = $model->PastorId;
   
                           if (!($flag = $modelShortTerm->save(false))) {
                               break;
                           }
   
                           if (isset($modelsShortTermMissional[$indexShortTerm]) && is_array($modelsShortTermMissional[$indexShortTerm])) {
                               foreach ($modelsShortTermMissional[$indexShortTerm] as $indexMissional => $modelShortTermMissional) {
                                   $modelShortTermMissional->ShortTermGoalsId = $modelShortTerm->ShortTermGoalsId;
                                   if (!($flag = $modelShortTermMissional->save(false))) {
                                       break;
                                   }
                               }
                           }
                       }
   
                   }
                   if ($flag) {
                       $transaction->commit();
                       return $this->redirect(['view', 'id' => $model->PastorId]);
                   }
               } catch (Exception $e) {
                   $transaction->rollBack();
               }
           }
   
           //return $this->redirect(['view', 'id' => $model->GroupId]);
   
       }else {
           return $this->render('update', [
               'model' => $model,
               'modelsShortTerm' => (empty($modelsShortTerm)) ? [new Shorttermgoals] : $modelsShortTerm,
                               'modelsShortTermMissional' => (empty($modelsShortTermMissional)) ? [[new Shorttermmissionalgoals]] : $modelsShortTermMissional,
           ]);
       }
   }

I am using Modelshortterm,

<?php

namespace app\models;

use Yii;
use yii\helpers\ArrayHelper;

class Modelshortterm extends \yii\base\Model
{
    /**
     * Creates and populates a set of models.
     *
     * @param string $modelClass
     * @param array $multipleModels
     * @return array
     */
    public static function createMultiple($modelClass, $multipleModels = [])
    {
        $model    = new $modelClass;
        $formName = $model->formName();
        $post     = Yii::$app->request->post($formName);
        $models   = [];

        if (! empty($multipleModels)) {
            $keys = array_keys(ArrayHelper::map($multipleModels, 'ShortTermGoalsId', 'ShortTermGoalsId'));
            $multipleModels = array_combine($keys, $multipleModels);
        }

        if ($post && is_array($post)) {
            foreach ($post as $i => $item) {
                if (isset($item['ShortTermGoalsId']) && !empty($item['ShortTermGoalsId']) && isset($multipleModels[$item['ShortTermGoalsId']])) {
                    $models[] = $multipleModels[$item['ShortTermGoalsId']];
                } else {
                    $models[] = new $modelClass;
                }
            }
        }

        unset($model, $formName, $post);

        return $models;
    }
}

Below is the image