[Notice] Trying to get property of non-object

Source

3 class CrestIdeasPage extends Extension
4 {
5     private static $allowed_actions = array(
6     	'crest_raty',
7     );
8 
9     public function init()
10     {
11         $params = [
12             "link" => '/home/projects?category='. $this->owner->Categories()->first()->ID
13         ];
14         Requirements::javascriptTemplate('mysite/javascript/custom.js', $params);
15 
16     }
17 
18     public function crest_raty(SS_HTTPRequest $r)

Trace

• CrestIdeasPage->init(,,,,,,)
  Object.php:1065
• Object->extend(init)
  MlbcController.php:712
• MlbcController->init()
  Page.php:22
• Page_Controller->init()
  IdeasPage.php:432
• IdeasPage_Controller->init()
  Controller.php:143
• Controller->handleRequest(SS_HTTPRequest,DataModel)
  ContentController.php:174
• ContentController->handleRequest(SS_HTTPRequest,DataModel)
  ContentController.php:154
• ContentController->handleRequest(SS_HTTPRequest,DataModel)
  ModelAsController.php:75
• ModelAsController->handleRequest(SS_HTTPRequest,DataModel)
  Director.php:385
• Director::handleRequest(SS_HTTPRequest,Session,DataModel)
  Director.php:149
• Director::direct(/saisons-precedentes/les-projets-laureats-2021/,DataModel)
  main.php:191