diff --git a/app/api/users/route.ts b/app/api/users/route.ts
index 0bdfb40..82c7918 100644
--- a/app/api/users/route.ts
+++ b/app/api/users/route.ts
@@ -54,8 +54,8 @@ export async function GET(request: NextRequest) {
         GROUP BY judge_id
       ) review_stats ON u.id = review_stats.judge_id
       ORDER BY u.created_at DESC 
-      LIMIT ? OFFSET ?
-    `, [limit, offset]);
+      LIMIT ${limit} OFFSET ${offset}
+    `);
     
     // 分頁資訊
     const totalPages = Math.ceil(total / limit);
diff --git a/components/admin/admin-layout.tsx b/components/admin/admin-layout.tsx
index 160cd7c..80a1426 100644
--- a/components/admin/admin-layout.tsx
+++ b/components/admin/admin-layout.tsx
@@ -171,7 +171,7 @@ export function AdminLayout({ children, currentPage, onPageChange }: AdminLayout
     setShowLogoutDialog(false)
 
     // Check if this is a popup/new tab opened from main site
-    if (window.opener && !window.opener.closed) {
+    if (typeof window !== 'undefined' && window.opener && !window.opener.closed) {
       // If opened from another window, close this tab and focus parent
       window.opener.focus()
       window.close()
@@ -214,7 +214,7 @@ export function AdminLayout({ children, currentPage, onPageChange }: AdminLayout
               <Button onClick={() => (window.location.href = "/")} variant="outline">
                 返回首頁
               </Button>
-              {window.opener && !window.opener.closed && (
+              {typeof window !== 'undefined' && window.opener && !window.opener.closed && (
                 <Button
                   onClick={() => {
                     window.opener.focus()
diff --git a/components/admin/user-management.tsx b/components/admin/user-management.tsx
index 91206b1..4dc9640 100644
--- a/components/admin/user-management.tsx
+++ b/components/admin/user-management.tsx
@@ -85,7 +85,9 @@ export function UserManagement() {
           const usersData = await usersResponse.json()
           setUsers(usersData.users || [])
         } else {
-          console.error('獲取用戶列表失敗')
+          const errorData = await usersResponse.json().catch(() => ({}))
+          console.error('獲取用戶列表失敗:', errorData.error || usersResponse.statusText)
+          setError(errorData.error || '獲取用戶列表失敗')
         }
 
         // 獲取統計資料
@@ -99,7 +101,8 @@ export function UserManagement() {
           const statsData = await statsResponse.json()
           setStats(statsData)
         } else {
-          console.error('獲取統計資料失敗')
+          const errorData = await statsResponse.json().catch(() => ({}))
+          console.error('獲取統計資料失敗:', errorData.error || statsResponse.statusText)
         }
       } catch (error) {
         console.error('載入資料失敗:', error)