diff --git a/config.php b/config.php
index 399aa48..7beda22 100755
--- a/config.php
+++ b/config.php
@@ -47,30 +47,36 @@ $twig->addGlobal('delete_part_confirm', $translator->trans('Are you sure you wan
 $twig->addGlobal('delete_category_confirm', $translator->trans('Are you sure you want to delete this category?'));
 
 // Build category tree for sidebar
-$db = App\Database\Database::getInstance();
-$categories = App\Models\Category::getAll($db);
-$items = App\Models\Item::getAll($db);
+try {
+    $db = App\Database\Database::getInstance();
+    $categories = App\Models\Category::getAll($db);
+    $items = App\Models\Item::getAll($db);
 
-function buildTree($categories, $items, $parentId = null) {
-    $tree = [];
-    foreach ($categories as $cat) {
-        if ($cat['parent_id'] == $parentId) {
-            $node = [
-                'id' => $cat['id'],
-                'name' => $cat['name'],
-                'children' => buildTree($categories, $items, $cat['id']),
-                'items' => []
-            ];
-            foreach ($items as $item) {
-                if ($item['category_id'] == $cat['id']) {
-                    $node['items'][] = $item;
+    function buildTree($categories, $items, $parentId = null, &$visited = []) {
+        $tree = [];
+        foreach ($categories as $cat) {
+            if ($cat['parent_id'] == $parentId && !in_array($cat['id'], $visited)) {
+                $visited[] = $cat['id'];
+                $node = [
+                    'id' => $cat['id'],
+                    'name' => $cat['name'],
+                    'children' => buildTree($categories, $items, $cat['id'], $visited),
+                    'items' => []
+                ];
+                foreach ($items as $item) {
+                    if ($item['category_id'] == $cat['id']) {
+                        $node['items'][] = $item;
+                    }
                 }
+                $tree[] = $node;
             }
-            $tree[] = $node;
         }
+        return $tree;
     }
-    return $tree;
-}
 
-$categoryTree = buildTree($categories, $items);
+    $categoryTree = buildTree($categories, $items);
+} catch (Exception $e) {
+    error_log('Error building category tree: ' . $e->getMessage());
+    $categoryTree = [];
+}
 $twig->addGlobal('category_tree', $categoryTree);