@@ -7,6 +7,9 @@ Latest
 * [#84](https://github.com/cleverage/ui-process-bundle/issues/84) Add `LogRecord::hasContextInfo()`, deprecate the misnamed `LogRecord::contextIsEmpty()` (it returns `true` when the context is not empty). Add tests.
 * [#85](https://github.com/cleverage/ui-process-bundle/issues/85) `ProcessHandler`: default report increment level aligned on the bundle configuration (`Warning`); declare the `symfony/ux-twig-component` dependency. Add tests.
 
+## Fixes
+* [#89](https://github.com/cleverage/ui-process-bundle/issues/89) `ProcessConfigurationsManager`: resolve the `ui.default` option with a normalizer instead of nested options defined with `setDefault()` (deprecated since symfony/options-resolver 7.3, removed in 8.0). With Symfony 8, a process launched with the UI form (`ui_launch_mode: form`) without `ui.default` no longer fails (`Cannot use object of type Closure as array`), and `ui.default` is validated again. Add tests.
+
 v3.0.2
 ------
 
 
@@ -83,16 +83,26 @@ private function resolveUiOptions(array $options): array
                     'ui_launch_mode' => 'modal',
                     'constraints' => [],
                     'run' => null,
-                    'default' => static function (OptionsResolver $defaultResolver) {
-                        $defaultResolver->setDefault('input', null);
-                        $defaultResolver->setDefault('context', static function (OptionsResolver $contextResolver) {
-                            $contextResolver->setPrototype(true);
-                            $contextResolver->setRequired(['key', 'value']);
-                        });
-                    },
+                    'default' => [],
                 ]
             );
             $uiResolver->setAllowedValues('entrypoint_type', ['text', 'file']);
+            // Resolved by a normalizer rather than as nested options: nested options defined with setDefault() are
+            // deprecated since symfony/options-resolver 7.3 and removed in 8.0, setOptions() does not exist before 7.3
+            $uiResolver->setAllowedTypes('default', 'array');
+            $uiResolver->setNormalizer('default', static function (Options $options, array $default): array {
+                $defaultResolver = new OptionsResolver();
+                $defaultResolver->setDefaults(['input' => null, 'context' => []]);
+                $defaultResolver->setAllowedTypes('context', 'array[]');
+                $defaultResolver->setNormalizer('context', static function (Options $options, array $context): array {
+                    $contextResolver = new OptionsResolver();
+                    $contextResolver->setRequired(['key', 'value']);
+
+                    return array_map($contextResolver->resolve(...), $context);
+                });
+
+                return $defaultResolver->resolve($default);
+            });
             $uiResolver->setNormalizer('constraints', static fn (Options $options, array $values): array => (new ConstraintLoader())->buildConstraints($values));
             $uiResolver->setAllowedValues('ui_launch_mode', ['modal', null, 'form']);
 
 
@@ -73,11 +73,6 @@ clever_age_process:
                 ui:
                     ui_launch_mode: form
                     entrypoint_type: file
-                    # Required with Symfony 8: without it, ProcessConfigurationsManager returns the `default` nested
-                    # options closure (nested options defined with setDefault() are no longer supported)
-                    default:
-                        input: 'not used by a file input'
-                        context: []
             tasks:
                 data:
                     service: '@CleverAge\ProcessBundle\Task\DummyTask'
 
@@ -121,8 +121,10 @@ public function testLaunchWithFileUpload(): void
         $file = tempnam(sys_get_temp_dir(), 'upload');
         file_put_contents((string) $file, 'line1');
 
+        // test.upload has no "default" UI option: the form must be displayed with empty default values
         $crawler = $this->client->request('GET', '/process?routeName=process_launch&process=test.upload');
         self::assertResponseIsSuccessful();
+        self::assertCount(0, $crawler->filter('input[name^="launch[context]"]'));
         self::assertCount(1, $crawler->filter('input[type="file"][name="launch[input]"]'));
 
         $form = $crawler->selectButton('Launch')->form();
 
@@ -17,8 +17,12 @@
 use CleverAge\ProcessBundle\Registry\ProcessConfigurationRegistry;
 use CleverAge\UiProcessBundle\Manager\ProcessConfigurationsManager;
 use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\TestCase;
+use Symfony\Component\OptionsResolver\Exception\ExceptionInterface as OptionsResolverException;
 use Symfony\Component\OptionsResolver\Exception\InvalidOptionsException;
+use Symfony\Component\OptionsResolver\Exception\MissingOptionsException;
+use Symfony\Component\OptionsResolver\Exception\UndefinedOptionsException;
 use Symfony\Component\Validator\Constraints\Length;
 use Symfony\Component\Validator\Constraints\NotBlank;
 
@@ -59,9 +63,7 @@ public function testDefaultUiOptions(): void
         /** @var mixed $run the PHPDoc type of the option is wrong */
         $run = $options['run'];
         self::assertNull($run);
-        // The "default" nested option is not asserted: defined with setDefault() and a closure, it is not resolved as
-        // a nested option with symfony/options-resolver 8 (the closure itself is returned)
-        self::assertArrayHasKey('default', $options);
+        self::assertSame(['input' => null, 'context' => []], $options['default']);
     }
 
     public function testConfiguredUiOptions(): void
@@ -100,6 +102,54 @@ public function testConfiguredUiOptions(): void
         self::assertSame(10, $options['constraints'][1]->max);
     }
 
+    public function testDefaultWithoutContext(): void
+    {
+        $manager = $this->createManager([
+            'test.process' => $this->rawProcess(['ui' => ['default' => ['input' => 'data.csv']]]),
+        ]);
+
+        $options = $manager->getUiOptions('test.process');
+
+        self::assertNotNull($options);
+        self::assertSame(['input' => 'data.csv', 'context' => []], $options['default']);
+    }
+
+    /**
+     * @param array<string, mixed>                   $default
+     * @param class-string<OptionsResolverException> $exception
+     */
+    #[DataProvider('provideInvalidDefault')]
+    public function testInvalidDefault(array $default, string $exception): void
+    {
+        $manager = $this->createManager(['test.process' => $this->rawProcess(['ui' => ['default' => $default]])]);
+
+        $this->expectException($exception);
+        $manager->getUiOptions('test.process');
+    }
+
+    /**
+     * @return iterable<string, array{array<string, mixed>, class-string<OptionsResolverException>}>
+     */
+    public static function provideInvalidDefault(): iterable
+    {
+        yield 'unknown option' => [['inputs' => 'data.csv'], UndefinedOptionsException::class];
+        yield 'context is not an array' => [['context' => 'foo'], InvalidOptionsException::class];
+        yield 'context item is not an array' => [['context' => ['foo']], InvalidOptionsException::class];
+        yield 'context item without value' => [['context' => [['key' => 'foo']]], MissingOptionsException::class];
+        yield 'context item with an unknown option' => [
+            ['context' => [['key' => 'foo', 'value' => 'bar', 'type' => 'string']]],
+            UndefinedOptionsException::class,
+        ];
+    }
+
+    public function testDefaultIsNotAnArray(): void
+    {
+        $manager = $this->createManager(['test.process' => $this->rawProcess(['ui' => ['default' => 'data.csv']])]);
+
+        $this->expectException(InvalidOptionsException::class);
+        $manager->getUiOptions('test.process');
+    }
+
     public function testInvalidEntrypointType(): void
     {
         $manager = $this->createManager(['test.process' => $this->rawProcess(['ui' => ['entrypoint_type' => 'csv']])]);