diff --git a/CHANGELOG.md b/CHANGELOG.md
index 30e3c1c..fa5fae5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,19 @@ getaggte Releases (Kanal `stable`, optional `beta`) — niemals Entwicklungs-Bui
 
 _Keine offenen Änderungen — der nächste Stand wird hier gesammelt und als `vX.Y.Z` getaggt._
 
+## [0.9.15] - 2026-06-19
+
+### Behoben
+- **Dashboard-Update/-Neustart hingen auf Hosts, deren `clusev`-Nutzer nicht uid 1002 hat.** Das
+  Prod-Image baute den `app`-Nutzer fest mit uid 1002, während `install.sh` das bind-gemountete
+  `./run` dem `clusev`-Nutzer (z. B. uid 1000) übergibt. Dadurch konnte der App-Prozess die
+  Sentinel-Datei nicht schreiben — der Knopf zeigte „läuft", aber auf dem Server passierte nichts.
+  Das Image wird jetzt mit `APP_UID/APP_GID = HOST_UID/HOST_GID` (dem `clusev`-Nutzer) gebaut, sodass
+  App-Prozess und `./run` übereinstimmen. **Einmalig per `sudo ./update.sh` neu bauen**, danach
+  funktioniert der Knopf (der konnte sich nicht selbst reparieren, da genau das Schreiben kaputt war).
+- **Fehlgeschlagenes Sentinel-Schreiben wird jetzt gemeldet** statt eines ewigen „läuft": geht das
+  Schreiben schief, erscheint ein Fehler-Toast mit dem Hinweis auf `sudo ./update.sh`.
+
 ## [0.9.14] - 2026-06-19
 
 ### Geändert
diff --git a/app/Livewire/Versions/Index.php b/app/Livewire/Versions/Index.php
index 88a4b10..e08ca26 100644
--- a/app/Livewire/Versions/Index.php
+++ b/app/Livewire/Versions/Index.php
@@ -197,7 +197,13 @@ class Index extends Component
         }
         RateLimiter::hit($key, 600);
 
-        $deployment->requestUpdate();
+        // Write the sentinel; if it can't be written (e.g. the bind-mounted dir isn't writable by
+        // the app user), surface that instead of a "running" state that would never resolve.
+        if (! $deployment->requestUpdate()) {
+            $this->dispatch('notify', message: __('versions.update_write_failed'), level: 'error');
+
+            return;
+        }
         // Persist the in-progress state in Redis (NOT the consumed sentinel) so the "läuft" notice
         // survives a reload AND the app rebuild; auto-expires as a backstop. Completion = version
         // moves past this base. 15 min TTL > the poll timeout, so a reload can still resume.
diff --git a/app/Services/DeploymentService.php b/app/Services/DeploymentService.php
index 2227a6d..35f099c 100644
--- a/app/Services/DeploymentService.php
+++ b/app/Services/DeploymentService.php
@@ -213,7 +213,7 @@ class DeploymentService
      * (rebuild, migrate, restart) — then removes the sentinel. The container never runs git or
      * Docker itself; it only writes this non-sensitive marker. Never throws.
      */
-    public function requestUpdate(): void
+    public function requestUpdate(): bool
     {
         $path = $this->updateSignalPath();
         $dir = dirname($path);
@@ -222,7 +222,9 @@ class DeploymentService
             @mkdir($dir, 0775, true);
         }
 
-        @file_put_contents($path, now()->toIso8601String().PHP_EOL);
+        // Returns false when the (bind-mounted) sentinel dir is not writable by the app user —
+        // the caller surfaces that instead of showing a "running" state that never resolves.
+        return @file_put_contents($path, now()->toIso8601String().PHP_EOL) !== false;
     }
 
     /** True while an update request is pending (the host watcher clears it once handled). */
diff --git a/config/clusev.php b/config/clusev.php
index f35d46c..a85a1f2 100644
--- a/config/clusev.php
+++ b/config/clusev.php
@@ -2,7 +2,7 @@
 
 return [
     // First tagged release is v0.1.0 (semantic, not -dev).
-    'version' => '0.9.14',
+    'version' => '0.9.15',
 
     // Deployed commit + branch. install.sh bakes these into .env from the host's .git (the prod
     // image ships no .git); the Versions page prefers them and falls back to a live .git read in
diff --git a/docker-compose.prod.yml b/docker-compose.prod.yml
index b7c4a4a..7efa38b 100644
--- a/docker-compose.prod.yml
+++ b/docker-compose.prod.yml
@@ -31,6 +31,13 @@ services:
       context: .
       dockerfile: Dockerfile
       target: prod
+      args:
+        # Build the in-image `app` user with the HOST's clusev uid/gid so php-fpm can write the
+        # bind-mounted ./run sentinel (install.sh chowns ./run to clusev). Without this the image
+        # defaults to 1002 and on a host where clusev != 1002 the dashboard restart/update buttons
+        # silently fail to write their sentinel. install.sh sets HOST_UID/HOST_GID from clusev.
+        APP_UID: "${HOST_UID:-1002}"
+        APP_GID: "${HOST_GID:-1002}"
     expose:
       - "80"
     volumes:
diff --git a/lang/de/versions.php b/lang/de/versions.php
index 424fb1b..7020fd7 100644
--- a/lang/de/versions.php
+++ b/lang/de/versions.php
@@ -52,6 +52,7 @@ return [
     'update_running' => 'Update läuft — Stack wird neu gebaut. Bitte gleich neu laden.',
     'update_not_available' => 'Kein Update verfügbar — die installierte Version ist bereits aktuell.',
     'update_throttled' => 'Zu viele Update-Anfragen — bitte in :seconds Sekunden erneut versuchen.',
+    'update_write_failed' => 'Update konnte nicht angestoßen werden (Sentinel nicht schreibbar). Bitte einmalig per SSH „sudo ./update.sh" aktualisieren.',
     'update_done' => 'Update abgeschlossen — jetzt auf v:version.',
     'update_stalled' => 'Update dauert ungewöhnlich lange — Logs prüfen (journalctl -u clusev-update.service) oder Seite neu laden.',
 
diff --git a/lang/en/versions.php b/lang/en/versions.php
index 79e2208..ae36ba3 100644
--- a/lang/en/versions.php
+++ b/lang/en/versions.php
@@ -52,6 +52,7 @@ return [
     'update_running' => 'Update in progress — the stack is rebuilding. Reload shortly.',
     'update_not_available' => 'No update available — the installed version is already current.',
     'update_throttled' => 'Too many update requests — try again in :seconds seconds.',
+    'update_write_failed' => 'Could not start the update (sentinel not writable). Please update once via SSH with "sudo ./update.sh".',
     'update_done' => 'Update complete — now on v:version.',
     'update_stalled' => 'Update is taking unusually long — check the logs (journalctl -u clusev-update.service) or reload.',
 
diff --git a/tests/Feature/VersionUpdateCheckTest.php b/tests/Feature/VersionUpdateCheckTest.php
index 649cc2d..ce51a43 100644
--- a/tests/Feature/VersionUpdateCheckTest.php
+++ b/tests/Feature/VersionUpdateCheckTest.php
@@ -224,6 +224,21 @@ class VersionUpdateCheckTest extends TestCase
             ->assertSee('feat/v1-foundation');
     }
 
+    public function test_update_surfaces_an_error_when_the_sentinel_cannot_be_written(): void
+    {
+        config()->set('clusev.version', '0.9.10');
+        Http::fake([self::TAGS_URL => Http::response([['name' => 'v0.9.14']])]);
+        $mock = \Mockery::mock(DeploymentService::class)->makePartial();
+        $mock->shouldReceive('requestUpdate')->andReturn(false); // unwritable sentinel dir
+        $this->app->instance(DeploymentService::class, $mock);
+
+        Livewire::test(Index::class)
+            ->call('requestUpdate')
+            ->assertSet('updateRequested', false);
+
+        $this->assertNull(Cache::get('clusev:update-in-progress'), 'no in-progress marker when the sentinel write failed');
+    }
+
     public function test_request_update_is_throttled_per_user(): void
     {
         config()->set('clusev.version', '0.9.4');