diff --git a/saas-app/public/install-support.php b/saas-app/public/install-support.php
index 8ea913c..ae137f9 100644
--- a/saas-app/public/install-support.php
+++ b/saas-app/public/install-support.php
@@ -36,6 +36,11 @@ function scripts_installer_lock_path(): string
     return scripts_saas_app_path() . DIRECTORY_SEPARATOR . '.installer.lock';
 }
 
+function scripts_parent_directory(string $path): string
+{
+    return dirname($path);
+}
+
 function scripts_string_contains(string $haystack, string $needle): bool
 {
     if (function_exists('str_contains')) {
@@ -157,6 +162,46 @@ function scripts_write_env_file(array $values, ?string $targetPath = null): stri
     return $targetPath;
 }
 
+function scripts_path_writable_state(string $path): array
+{
+    $exists = file_exists($path);
+    $parent = scripts_parent_directory($path);
+    $targetWritable = $exists ? is_writable($path) : false;
+    $parentWritable = is_dir($parent) ? is_writable($parent) : false;
+
+    return [
+        'path' => $path,
+        'exists' => $exists,
+        'readable' => $exists ? is_readable($path) : false,
+        'writable' => $exists ? $targetWritable : $parentWritable,
+        'target_writable' => $targetWritable,
+        'parent' => $parent,
+        'parent_exists' => is_dir($parent),
+        'parent_writable' => $parentWritable,
+    ];
+}
+
+function scripts_path_state_label(array $state): string
+{
+    if (!$state['parent_exists']) {
+        return 'Elternordner fehlt';
+    }
+
+    if ($state['exists'] && $state['target_writable']) {
+        return 'beschreibbar';
+    }
+
+    if (!$state['exists'] && $state['parent_writable']) {
+        return 'anlegbar';
+    }
+
+    if ($state['exists']) {
+        return 'nicht beschreibbar';
+    }
+
+    return 'nicht anlegbar';
+}
+
 function scripts_format_env_value(string $value): string
 {
     if ($value === '') {
diff --git a/saas-app/public/install.php b/saas-app/public/install.php
index e316a4d..d4cb456 100644
--- a/saas-app/public/install.php
+++ b/saas-app/public/install.php
@@ -56,6 +56,9 @@ $errors = [];
 $executedMigrations = [];
 $bundlePath = is_file(scripts_bundle_output_path()) ? scripts_bundle_output_path() : null;
 $locked = scripts_installer_is_locked();
+$envPathState = scripts_path_writable_state(scripts_env_path());
+$lockPathState = scripts_path_writable_state(scripts_installer_lock_path());
+$bundlePathState = scripts_path_writable_state(scripts_bundle_output_path());
 
 if ($requestMethod === 'POST' && !$locked) {
     $csrf = (string) ($_POST['csrf'] ?? '');
@@ -118,7 +121,8 @@ if ($requestMethod === 'POST' && !$locked) {
                 if (scripts_string_contains($message, 'pdo_sqlsrv')) {
                     $errors[] = 'Migrationen konnten nicht direkt ueber PHP ausgefuehrt werden. Bitte `pdo_sqlsrv` pruefen oder das SQL-Bundle manuell importieren.';
                 } elseif (scripts_string_contains($message, '.env')) {
-                    $errors[] = 'Die Konfiguration konnte nicht gespeichert werden. Bitte Schreibrechte pruefen.';
+                    $errors[] = 'Die Konfiguration konnte nicht gespeichert werden. Zielpfad: ' . scripts_env_path();
+                    $errors[] = 'Status fuer .env: ' . scripts_path_state_label($envPathState) . '. Elternordner: ' . $envPathState['parent'];
                 } else {
                     $errors[] = 'Die Installation konnte nicht abgeschlossen werden. Bitte Eingaben, DB-Zugang und Dateirechte pruefen.';
                 }
@@ -439,9 +443,15 @@ function h(string $value): string
                 <li>PHP Version: <code><?= h(PHP_VERSION) ?></code></li>
                 <li>.env.example: <code><?= is_file(scripts_env_example_path()) ? 'vorhanden' : 'fehlt' ?></code></li>
                 <li>.env: <code><?= is_file(scripts_env_path()) ? 'vorhanden' : 'fehlt' ?></code></li>
+                <li>.env Status: <code><?= h(scripts_path_state_label($envPathState)) ?></code></li>
+                <li>.env Zielpfad: <code><?= h($envPathState['path']) ?></code></li>
+                <li>.env Elternordner: <code><?= h($envPathState['parent']) ?></code></li>
+                <li>.env Elternordner beschreibbar: <code><?= $envPathState['parent_writable'] ? 'ja' : 'nein' ?></code></li>
                 <li>pdo_sqlsrv: <code><?= extension_loaded('pdo_sqlsrv') ? 'aktiv' : 'nicht geladen' ?></code></li>
                 <li>Installer-Lock: <code><?= $locked ? 'aktiv' : 'offen' ?></code></li>
+                <li>Lock-Datei Status: <code><?= h(scripts_path_state_label($lockPathState)) ?></code></li>
                 <li>Bundle-Pfad: <code><?= h(scripts_bundle_output_path()) ?></code></li>
+                <li>Bundle-Ziel Status: <code><?= h(scripts_path_state_label($bundlePathState)) ?></code></li>
             </ul>
 
             <?php if ($bundlePath !== null): ?>