diff --git a/src/CoreBundle/Migrations/Schema/V200/Version20251007110500.php b/src/CoreBundle/Migrations/Schema/V200/Version20251007110500.php
new file mode 100644
index 00000000000..808a600425b
--- /dev/null
+++ b/src/CoreBundle/Migrations/Schema/V200/Version20251007110500.php
@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+/* For licensing terms, see /license.txt */
+
+namespace Chamilo\CoreBundle\Migrations\Schema\V200;
+
+use Chamilo\CoreBundle\Migrations\AbstractMigrationChamilo;
+use Doctrine\DBAL\Schema\Schema;
+
+final class Version20251007110500 extends AbstractMigrationChamilo
+{
+    public function getDescription(): string
+    {
+        return 'Make c_blog_task.description nullable and drop invalid default on TEXT/LONGTEXT.';
+    }
+
+    public function up(Schema $schema): void
+    {
+        $this->addSql('ALTER TABLE c_blog_task MODIFY description LONGTEXT NULL');
+    }
+
+    public function down(Schema $schema): void
+    {
+        $this->addSql('UPDATE c_blog_task SET description = "" WHERE description IS NULL');
+        $this->addSql('ALTER TABLE c_blog_task MODIFY description LONGTEXT NOT NULL');
+    }
+}
diff --git a/src/CourseBundle/Entity/CBlogTask.php b/src/CourseBundle/Entity/CBlogTask.php
index 97e91068ef4..4de2a454629 100644
--- a/src/CourseBundle/Entity/CBlogTask.php
+++ b/src/CourseBundle/Entity/CBlogTask.php
@@ -49,7 +49,7 @@ class CBlogTask
     #[Groups(['blog_task:read', 'blog_task:write', 'task_rel_user:read'])]
     protected string $title;
 
-    #[ORM\Column(name: 'description', type: 'text', nullable: false, options: ['default' => ''])]
+    #[ORM\Column(name: 'description', type: 'text', nullable: true)]
     #[Groups(['blog_task:read', 'blog_task:write'])]
     protected string $description = '';
 
@@ -102,7 +102,7 @@ public function setTitle(string $title): self
 
     public function getDescription(): string
     {
-        return $this->description;
+        return $this->description ?? '';
     }
 
     public function setDescription(string $description): self