From 853450d7d1278dcbea426edb720b96d883142af0 Mon Sep 17 00:00:00 2001
From: brandonkelly <brandon@pixelandtonic.com>
Date: Wed, 11 Sep 2024 21:50:07 +0200
Subject: [PATCH] Slugs are not essential

---
 CHANGELOG.md         | 1 +
 src/base/Element.php | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1d0d332d516..b96b79fa8dc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,7 @@
 
 - Updated Twig to 3.14. ([#15704](https://github.com/craftcms/cms/issues/15704))
 - Fixed a bug where address’ Label fields were being marked as translatable. ([#15702](https://github.com/craftcms/cms/pull/15702))
+- Fixed an error that could occur when saving an entry with a Matrix field, if the nested entries didn’t have slugs.
 - Fixed an RCE vulnerability.
 
 ## 5.4.2 - 2024-09-06
diff --git a/src/base/Element.php b/src/base/Element.php
index ee8915a017e..785433bf668 100644
--- a/src/base/Element.php
+++ b/src/base/Element.php
@@ -2638,7 +2638,7 @@ protected function defineRules(): array
                 ['slug'],
                 'required',
                 'when' => fn() => (bool)preg_match('/\bslug\b/', $this->getUriFormat() ?? ''),
-                'on' => [self::SCENARIO_DEFAULT, self::SCENARIO_LIVE, self::SCENARIO_ESSENTIALS],
+                'on' => [self::SCENARIO_DEFAULT, self::SCENARIO_LIVE],
             ];
             $rules[] = [['uri'], ElementUriValidator::class, 'on' => [self::SCENARIO_DEFAULT, self::SCENARIO_LIVE, self::SCENARIO_ESSENTIALS]];
         }