Fix use case:Plugin.Hierarchy deep nested when no hasMany association.

app/src/View/Helper/TabHelper.php

@@ -245,11 +245,16 @@ public function getCurrentId(string $tabName = null, bool $isNested = false): in
   public function getHasManyAssociationModels(string $modelName): \Generator
   {
     $model = TableRegistry::getTableLocator()->get($modelName);
-    // We'll start by obtaining the set of models directly associated with the CO model.
-    $associations = $model->associations();
+    // We'll start by getting the set of models directly associated with the CO model.
+    $associations = $model->associations()->getByType(['hasMany', 'hasOne']);
+
+    if(empty($associations)) {
+      // Yield null if empty
+      yield;
+    }
 
-    foreach($associations->getByType(['hasMany', 'hasOne']) as $ta) {
-      $this>$this->setAssociation($ta->getClassName());
+    foreach($associations as $ta) {
+      $this->setAssociation($ta->getClassName());
       yield $ta->getClassName();
     }
   }

app/templates/element/subnavigation/inlineList.php

@@ -36,9 +36,21 @@
 ?>
 
 <?php foreach($vv_subnavigation_nested['tabs'] as $tab): ?>
+  <?php
+  // calculate the id
+  $curId = $this->Tab->getCurrentId($tab, $isNested);
+  // Check if there are child models. If not continue
+  if (str_contains($tab, '.Hierarchy')) {
+    $modelName = $this->Tab->retrievePluginName($tab, (int)$curId);
+    [$plugin, ] = explode('.', $modelName);
+    if($this->Tab->getHasManyAssociationModels($modelName)->current() === null) {
+      continue;
+    }
+  }
+
+  ?>
   <li class="list-inline-item">
     <?php
-    $curId = $this->Tab->getCurrentId($tab, $isNested);
     // Construct Element Title
     $title = $this->element('subnavigation/tabTitle', compact('tab', 'curId', 'isNested'));
     // Construct Target URL