diff --git a/public_html/_incl/db.php b/public_html/_incl/db.php
index 5980588..ce53f17 100644
--- a/public_html/_incl/db.php
+++ b/public_html/_incl/db.php
@@ -4,12 +4,12 @@
  *
  * Provides a PDO SQLite connection and a lightweight migration runner.
  * All application data previously stored as JSON files under /DATA is now
- * persisted in /DATA/axia4.db.
+ * persisted in /DATA/axia4.sqlite.
  *
  * Usage:  db()  → returns the shared PDO instance (auto-migrates on first call).
  */
 
-define('DB_PATH',        '/DATA/axia4.db');
+define('DB_PATH',        '/DATA/axia4.sqlite');
 define('MIGRATIONS_DIR', __DIR__ . '/migrations');
 
 // ── Connection ────────────────────────────────────────────────────────────────
diff --git a/public_html/_incl/migrations/002_import_json.php b/public_html/_incl/migrations/002_import_json.php
index cbc5e9c..869c674 100644
--- a/public_html/_incl/migrations/002_import_json.php
+++ b/public_html/_incl/migrations/002_import_json.php
@@ -63,8 +63,9 @@ if (is_dir($users_dir)) {
         $user_id = (int) $db->lastInsertId();
         if ($user_id === 0) {
             // Already existed – look it up
-            $row = $db->prepare("SELECT id FROM users WHERE username = ?")->execute([$username]);
-            $user_id = (int) $db->query("SELECT id FROM users WHERE username = " . $db->quote($username))->fetchColumn();
+            $stmt2 = $db->prepare("SELECT id FROM users WHERE username = ?");
+            $stmt2->execute([$username]);
+            $user_id = (int) $stmt2->fetchColumn();
         }
 
         // Entreaulas centro assignment
diff --git a/public_html/sysadmin/aularios.php b/public_html/sysadmin/aularios.php
index 1a1651b..434e717 100644
--- a/public_html/sysadmin/aularios.php
+++ b/public_html/sysadmin/aularios.php
@@ -72,8 +72,11 @@ switch ($form_action) {
             Sf($_POST["name"] ?? ""),
             Sf($_POST["icon"] ?? "/static/logo-entreaulas.png"),
         ]);
-        // Create Alumnos directory for photo-based features
-        @mkdir("/DATA/entreaulas/Centros/$centro_id/Aularios/$aulario_id/Proyectos/", 0755, true);
+        // Create Proyectos directory for project file storage
+        $proyectos_dir = "/DATA/entreaulas/Centros/$centro_id/Aularios/$aulario_id/Proyectos/";
+        if (!is_dir($proyectos_dir)) {
+            mkdir($proyectos_dir, 0755, true);
+        }
         header("Location: ?action=index");
         exit();
         break;
diff --git a/public_html/sysadmin/centros.php b/public_html/sysadmin/centros.php
index 2aa6be5..e4de35f 100644
--- a/public_html/sysadmin/centros.php
+++ b/public_html/sysadmin/centros.php
@@ -32,8 +32,8 @@ switch ($form_action) {
         db()->prepare("INSERT INTO centros (centro_id) VALUES (?)")->execute([$centro_id]);
         // Keep filesystem directory for activity photos (Panel/Actividades)
         $centro_path = "/DATA/entreaulas/Centros/$centro_id";
-        if (!is_dir($centro_path)) {
-            mkdir($centro_path, 0755, true);
+        if (!is_dir($centro_path) && !mkdir($centro_path, 0755, true) && !is_dir($centro_path)) {
+            error_log("centros.php: failed to create directory $centro_path");
         }
         header("Location: ?action=index");
         exit();