diff --git a/include/nc_connector_webdav.inc.php b/include/nc_connector_webdav.inc.php
index e4b5596..4c23270 100644
--- a/include/nc_connector_webdav.inc.php
+++ b/include/nc_connector_webdav.inc.php
@@ -5,46 +5,24 @@ if (!defined('PHPWG_ROOT_PATH'))
 }
 
 /**
- * Return the only existing local connector as migration fallback.
+ * Link a WebDAV successor with the exact legacy connection selected for migration.
  */
-function bratonien_tools_nc_connector_single_local_fallback()
+function bratonien_tools_nc_connector_pair_migration_fallback($legacy_id, $webdav_id, array &$webdav_config, $now)
 {
-  bratonien_tools_nc_connector_ensure_table();
-  $table = bratonien_tools_nc_connector_table();
-  $result = pwg_query("SELECT id, enabled, takeover_state, config_json FROM `$table` WHERE adapter='local' ORDER BY id");
-  $rows = array();
-
-  while ($row = pwg_db_fetch_assoc($result))
+  $legacy_id = (int)$legacy_id;
+  $webdav_id = (int)$webdav_id;
+  if ($legacy_id < 1 || $webdav_id < 1 || $legacy_id === $webdav_id)
   {
-    $rows[] = $row;
-    if (count($rows) > 1) return null;
+    throw new RuntimeException('Die Migrationszuordnung ist ungueltig.');
   }
 
-  if (count($rows) !== 1) return null;
-
-  $row = $rows[0];
-  $config = json_decode((string)$row['config_json'], true);
-  if (!is_array($config)) $config = array();
-
-  return array(
-    'id'=>(int)$row['id'],
-    'enabled'=>(bool)$row['enabled'],
-    'takeover_state'=>(string)$row['takeover_state'],
-    'config'=>$config,
-  );
-}
-
-/**
- * Link a WebDAV connection with the single existing local fallback.
- */
-function bratonien_tools_nc_connector_pair_migration_fallback($webdav_id, array &$webdav_config, $now)
-{
-  $legacy = bratonien_tools_nc_connector_single_local_fallback();
-  if (!$legacy) return null;
-
-  $legacy_id = (int)$legacy['id'];
-  if ($legacy_id < 1 || $legacy_id === (int)$webdav_id) return null;
+  $legacy = bratonien_tools_nc_connector_connection($legacy_id, false);
+  if (!$legacy || (string)$legacy['adapter'] !== 'local')
+  {
+    throw new RuntimeException('Die ausgewaehlte Legacy-Verbindung fuer die Migration ist nicht mehr verfuegbar.');
+  }
 
+  $legacy_config = isset($legacy['config']) && is_array($legacy['config']) ? $legacy['config'] : array();
   $webdav_config['migration'] = array(
     'role'=>'webdav-primary-candidate',
     'legacy_fallback_connection_id'=>$legacy_id,
@@ -52,11 +30,9 @@ function bratonien_tools_nc_connector_pair_migration_fallback($webdav_id, array
     'paired_at'=>(string)$now,
     'cutover_state'=>'parallel',
   );
-
-  $legacy_config = $legacy['config'];
   $legacy_config['migration'] = array(
     'role'=>'legacy-fallback',
-    'webdav_successor_connection_id'=>(int)$webdav_id,
+    'webdav_successor_connection_id'=>$webdav_id,
     'fallback_policy'=>'keep-running',
     'paired_at'=>(string)$now,
     'cutover_state'=>'parallel',
@@ -69,7 +45,7 @@ function bratonien_tools_nc_connector_pair_migration_fallback($webdav_id, array
   }
 
   $table = bratonien_tools_nc_connector_table();
-  pwg_query("UPDATE `$table` SET config_json='".pwg_db_real_escape_string($legacy_json)."', updated='".pwg_db_real_escape_string((string)$now)."' WHERE id=".$legacy_id." LIMIT 1");
+  pwg_query("UPDATE `$table` SET config_json='".pwg_db_real_escape_string($legacy_json)."', updated='".pwg_db_real_escape_string((string)$now)."' WHERE id=".$legacy_id." AND adapter='local' LIMIT 1");
 
   return $legacy_id;
 }
@@ -77,9 +53,8 @@ function bratonien_tools_nc_connector_pair_migration_fallback($webdav_id, array
 /**
  * Create or update a WebDAV-backed connector from the user-facing wizard.
  *
- * Remote connections are updated in place. When the editor was opened for a
- * legacy connection, a WebDAV successor is created and the legacy connection
- * stays available as fallback.
+ * Remote connections are updated in place. A legacy connection is paired only
+ * when the wizard was explicitly opened in migration mode for that connection.
  */
 function bratonien_tools_nc_connector_create_webdav_placeholder_from_wizard()
 {
@@ -87,7 +62,7 @@ function bratonien_tools_nc_connector_create_webdav_placeholder_from_wizard()
 
   if (empty($state['scan_ok']) || empty($state['technical_complete']))
   {
-    throw new RuntimeException('Die WebDAV-Verbindung wurde im Assistenten noch nicht vollständig vorbereitet.');
+    throw new RuntimeException('Die WebDAV-Verbindung wurde im Assistenten noch nicht vollstaendig vorbereitet.');
   }
 
   $base_url = rtrim(trim((string)($state['base_url'] ?? '')), '/');
@@ -95,7 +70,7 @@ function bratonien_tools_nc_connector_create_webdav_placeholder_from_wizard()
   $password = (string)($state['_password'] ?? '');
   if ($base_url === '' || $username === '' || $password === '')
   {
-    throw new RuntimeException('Für den WebDAV-Zugang fehlen Nextcloud-Adresse oder Zugangsdaten.');
+    throw new RuntimeException('Fuer den WebDAV-Zugang fehlen Nextcloud-Adresse oder Zugangsdaten.');
   }
 
   $selected = isset($state['directory_selected']) && is_array($state['directory_selected'])
@@ -104,13 +79,13 @@ function bratonien_tools_nc_connector_create_webdav_placeholder_from_wizard()
   $selected_ids = isset($state['directory_selected_fileids']) && is_array($state['directory_selected_fileids'])
     ? $state['directory_selected_fileids']
     : array();
-  if (!$selected) throw new RuntimeException('Bitte mindestens ein Nextcloud-Verzeichnis auswählen.');
+  if (!$selected) throw new RuntimeException('Bitte mindestens ein Nextcloud-Verzeichnis auswaehlen.');
 
   $roots = array();
   foreach ($selected as $path)
   {
     $fileid = isset($selected_ids[$path]) ? (int)$selected_ids[$path] : 0;
-    if ($fileid < 1) throw new RuntimeException('Für ein ausgewähltes Nextcloud-Verzeichnis fehlt die eindeutige Datei-ID.');
+    if ($fileid < 1) throw new RuntimeException('Fuer ein ausgewaehltes Nextcloud-Verzeichnis fehlt die eindeutige Datei-ID.');
     $display_name = $path === ''
       ? (trim((string)($state['display_name'] ?? '')) !== '' ? trim((string)$state['display_name']) : $username)
       : basename($path);
@@ -139,6 +114,14 @@ function bratonien_tools_nc_connector_create_webdav_placeholder_from_wizard()
     && (string)$editing_connection['adapter'] === 'remote'
     && (string)($editing_connection['config']['source_mode'] ?? '') === 'webdav-placeholder'
     && $editing_mode === 'update';
+  $migrating_legacy = $editing_connection
+    && (string)$editing_connection['adapter'] === 'local'
+    && $editing_mode === 'migrate';
+
+  if ($editing_mode === 'migrate' && !$migrating_legacy)
+  {
+    throw new RuntimeException('Die fuer die Migration ausgewaehlte Legacy-Verbindung ist nicht mehr verfuegbar.');
+  }
 
   $config = array(
     'origin'=>'native',
@@ -202,12 +185,12 @@ function bratonien_tools_nc_connector_create_webdav_placeholder_from_wizard()
     $config_json = json_encode($config, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
     if (!is_string($config_json)) throw new RuntimeException('WebDAV-Konfiguration konnte nicht serialisiert werden.');
 
-    pwg_query("UPDATE `$table` SET name='".pwg_db_real_escape_string($name)."', config_json='".pwg_db_real_escape_string($config_json)."', secret_blob='".pwg_db_real_escape_string($secret_blob)."', updated='".pwg_db_real_escape_string($now)."' WHERE id=".$editing_id." LIMIT 1");
+    pwg_query("UPDATE `$table` SET name='".pwg_db_real_escape_string($name)."', config_json='".pwg_db_real_escape_string($config_json)."', secret_blob='".pwg_db_real_escape_string($secret_blob)."', updated='".pwg_db_real_escape_string($now)."' WHERE id=".$editing_id." AND adapter='remote' LIMIT 1");
     unset($_SESSION['bratonien_nc_wizard']);
 
     return array(
       'connection_id'=>$editing_id,
-      'message'=>'WebDAV-Verbindung #'.$editing_id.' wurde gespeichert. Der nächste Connector-Lauf verwendet die neuen Einstellungen.',
+      'message'=>'WebDAV-Verbindung #'.$editing_id.' wurde gespeichert. Der naechste Connector-Lauf verwendet die neuen Einstellungen.',
     );
   }
 
@@ -226,22 +209,26 @@ function bratonien_tools_nc_connector_create_webdav_placeholder_from_wizard()
   $id = (int)pwg_db_insert_id();
   if ($id < 1) throw new RuntimeException('Die WebDAV-Verbindung konnte nicht eindeutig angelegt werden.');
 
+  $legacy_fallback_id = null;
   try
   {
     $config['state_dir'] = '/var/lib/bratonien-tools/nc-connector/connection-'.$id;
     $config['status_file'] = $config['state_dir'].'/connector-status.json';
-    $legacy_fallback_id = bratonien_tools_nc_connector_pair_migration_fallback($id, $config, $now);
+    if ($migrating_legacy)
+    {
+      $legacy_fallback_id = bratonien_tools_nc_connector_pair_migration_fallback($editing_id, $id, $config, $now);
+    }
 
     $config_json = json_encode($config, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
     if (!is_string($config_json))
     {
       throw new RuntimeException('Die WebDAV-Verbindung konnte nach dem Anlegen nicht serialisiert werden.');
     }
-    pwg_query("UPDATE `$table` SET config_json='".pwg_db_real_escape_string($config_json)."' WHERE id=".$id." LIMIT 1");
+    pwg_query("UPDATE `$table` SET config_json='".pwg_db_real_escape_string($config_json)."' WHERE id=".$id." AND adapter='remote' LIMIT 1");
   }
   catch (Throwable $e)
   {
-    pwg_query("DELETE FROM `$table` WHERE id=".$id." LIMIT 1");
+    pwg_query("DELETE FROM `$table` WHERE id=".$id." AND adapter='remote' LIMIT 1");
     throw $e;
   }