fixed

Closes #3178828

src/ParamConverter/PluginTypeBasedConverterTrait.php

@@ -73,18 +73,21 @@ trait PluginTypeBasedConverterTrait {
   /**
    * Implements \Drupal\Core\ParamConverter\ParamConverterInterface::applies().
    */
-  public function applies($definition, $name, Route $route) {
+public function applies($definition, $name, Route $route) {
     $valid = $this->validateParameterDefinition($definition);
     if (!$valid) {
-      return FALSE;
+        return FALSE;
+    }
+    if (!is_array($definition)) {
+        return FALSE;
     }
 
     if (is_null($this->getConverterDefinition($definition))) {
-      return FALSE;
+        return FALSE;
     }
 
     return TRUE;
-  }
+}
 
   /**
    * Gets the converter-specific parameter definition.