diff --git a/app/Services/Admin/AdminSystemHealth.php b/app/Services/Admin/AdminSystemHealth.php
index 15b9cab5..9c01b05e 100644
--- a/app/Services/Admin/AdminSystemHealth.php
+++ b/app/Services/Admin/AdminSystemHealth.php
@@ -238,6 +238,19 @@ class AdminSystemHealth
                 : 'SESSION_SECURE_COOKIE ist aus'.($isLocal ? ' (lokal ok).' : ' — in https-Umgebungen aktivieren.'),
         ];
 
+        // Imagick trägt Herkunftsprüfung und KI-Vorab-Check der Bilder. Fehlt
+        // die Erweiterung, scheitern beide still (Bilder werden durchgelassen)
+        // — so geschehen auf Live bis 08.10.2026.
+        $precheckEnabled = (bool) config('images.precheck.enabled');
+        $checks[] = [
+            'key' => 'imagick',
+            'label' => 'PHP-Erweiterung Imagick',
+            'status' => $this->imagickAvailable() ? self::StatusOk : ($precheckEnabled ? self::StatusCritical : self::StatusWarn),
+            'detail' => $this->imagickAvailable()
+                ? 'Imagick ist geladen (Herkunftsprüfung und KI-Vorab-Check der Bilder).'
+                : 'Imagick fehlt — Herkunftsprüfung'.($precheckEnabled ? ' und KI-Vorab-Check' : '').' der Bilder laufen ins Leere. Auf dem Server php8.4-imagick installieren und PHP-FPM neu laden.',
+        ];
+
         // Herkunftsprüfung der Bild-Uploads (Bildkennzeichnung E.7): Fehler
         // der letzten sieben Tage zählen; Zustand D im Formular blockiert
         // nichts, muss aber sichtbar bleiben.
@@ -341,6 +354,11 @@ class AdminSystemHealth
         return $checks;
     }
 
+    protected function imagickAvailable(): bool
+    {
+        return class_exists(\Imagick::class);
+    }
+
     /**
      * @param  array<string, mixed>  $queue
      */
diff --git a/bootstrap/app.php b/bootstrap/app.php
index 0ff845d2..b97c4877 100644
--- a/bootstrap/app.php
+++ b/bootstrap/app.php
@@ -21,8 +21,11 @@ use Illuminate\Http\Request;
 use Illuminate\Support\Facades\Route;
 use Laravel\Sanctum\Http\Middleware\CheckAbilities;
 use Laravel\Sanctum\Http\Middleware\CheckForAnyAbility;
+use Livewire\Features\SupportFileUploads\MissingFileUploadsTraitException;
+use Livewire\Features\SupportLockedProperties\CannotUpdateLockedPropertyException;
 use Sentry\Laravel\Integration;
 use Symfony\Component\Console\Exception\CommandNotFoundException;
+use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
 
 return Application::configure(basePath: dirname(__DIR__))
     ->withRouting(
@@ -177,4 +180,18 @@ return Application::configure(basePath: dirname(__DIR__))
         // Vertippte artisan-Befehle sind kein Anwendungsfehler (GlitchTip
         // server-pressekonto, Issue 9: „config:cachels“ auf Live).
         $exceptions->dontReport(CommandNotFoundException::class);
+
+        // Manipulierte Livewire-Anfragen (Scanner, die gesperrte Properties
+        // setzen oder Uploads an Komponenten ohne Upload schicken) als 400
+        // beantworten statt als 500 bzw. 419 — Livewire weist sie korrekt ab,
+        // sie sind kein Anwendungsfehler und kein abgelaufenes Formular
+        // (GlitchTip server-pressekonto, Issues 38 und 39, 08.10.2026).
+        $exceptions->map(
+            CannotUpdateLockedPropertyException::class,
+            fn (CannotUpdateLockedPropertyException $e): BadRequestHttpException => new BadRequestHttpException('Ungültige Livewire-Anfrage.', $e),
+        );
+        $exceptions->map(
+            MissingFileUploadsTraitException::class,
+            fn (MissingFileUploadsTraitException $e): BadRequestHttpException => new BadRequestHttpException('Ungültige Livewire-Anfrage.', $e),
+        );
     })->create();
diff --git a/resources/js/error-reporting.js b/resources/js/error-reporting.js
index d2b474e6..65c6cddb 100644
--- a/resources/js/error-reporting.js
+++ b/resources/js/error-reporting.js
@@ -123,6 +123,12 @@ if (config?.dsn) {
     });
 
     window.addEventListener('unhandledrejection', (event) => {
+        // Alpine bricht laufende x-transition-Übergänge mit diesem Objekt ab
+        // (GlitchTip browser-pressekonto, Issue 18) — kein Fehler.
+        if (event.reason?.isFromCancelledTransition === true) {
+            return;
+        }
+
         capture(rejectionToError(event.reason));
     });
 }
diff --git a/tests/Feature/Admin/SystemHealthTest.php b/tests/Feature/Admin/SystemHealthTest.php
index da9be2e0..0898fd5f 100644
--- a/tests/Feature/Admin/SystemHealthTest.php
+++ b/tests/Feature/Admin/SystemHealthTest.php
@@ -124,3 +124,28 @@ test('snapshot flags pending media privatization', function () {
     expect($checks['media_privatization']['status'])->toBe('warn')
         ->and($checks['media_privatization']['detail'])->toContain('1');
 });
+
+test('snapshot flags a missing imagick extension', function (bool $precheckEnabled, string $status) {
+    config()->set('images.precheck.enabled', $precheckEnabled);
+    app()->bind(AdminSystemHealth::class, fn () => new class extends AdminSystemHealth
+    {
+        protected function imagickAvailable(): bool
+        {
+            return false;
+        }
+    });
+
+    $checks = collect(app(AdminSystemHealth::class)->snapshot()['checks'])->keyBy('key');
+
+    expect($checks['imagick']['status'])->toBe($status)
+        ->and($checks['imagick']['detail'])->toContain('php8.4-imagick');
+})->with([
+    'precheck off' => [false, 'warn'],
+    'precheck on' => [true, 'critical'],
+]);
+
+test('snapshot reports imagick as ok when it is loaded', function () {
+    $checks = collect(app(AdminSystemHealth::class)->snapshot()['checks'])->keyBy('key');
+
+    expect($checks['imagick']['status'])->toBe(class_exists(Imagick::class) ? 'ok' : 'warn');
+});
diff --git a/tests/Feature/Monitoring/ErrorReportingTest.php b/tests/Feature/Monitoring/ErrorReportingTest.php
index 9b2b8c1a..d02e22ab 100644
--- a/tests/Feature/Monitoring/ErrorReportingTest.php
+++ b/tests/Feature/Monitoring/ErrorReportingTest.php
@@ -2,7 +2,10 @@
 
 use App\Models\User;
 use App\Support\Monitoring\ErrorReportScrubber;
+use Illuminate\Contracts\Debug\ExceptionHandler;
 use Illuminate\Support\Facades\Route;
+use Livewire\Features\SupportFileUploads\MissingFileUploadsTraitException;
+use Livewire\Features\SupportLockedProperties\CannotUpdateLockedPropertyException;
 use Sentry\Event;
 use Sentry\ExceptionDataBag;
 use Sentry\SentrySdk;
@@ -44,6 +47,27 @@ test('a mistyped artisan command is not reported', function () {
     expect($glitchTip->events)->toBe([]);
 });
 
+test('tampered livewire requests are answered with 400 and not reported', function (Closure $makeException) {
+    $glitchTip = FakeGlitchTip::install();
+    $exception = $makeException();
+
+    report($exception);
+
+    $response = app(ExceptionHandler::class)->render(request(), $exception);
+
+    expect($glitchTip->events)->toBe([])
+        ->and($response->getStatusCode())->toBe(400);
+})->with([
+    'locked property' => fn () => new CannotUpdateLockedPropertyException('portal'),
+    'upload without trait' => fn () => new MissingFileUploadsTraitException(new class
+    {
+        public function getName(): string
+        {
+            return 'web.press-release-feed';
+        }
+    }),
+]);
+
 test('request data loses tokens, signatures and bodies', function () {
     $scrubbed = ErrorReportScrubber::scrubRequest([
         'url' => 'https://pressekonto.test/newsroom/claim/5?signature=abc123&expires=1700000000&src=mail_publish',