diff --git a/api/controllers/web/site.py b/api/controllers/web/site.py
index 4ca5ad05d9..e5c27c18c1 100644
--- a/api/controllers/web/site.py
+++ b/api/controllers/web/site.py
@@ -85,7 +85,7 @@ class AppSiteInfo:
         if can_replace_logo:
             base_url = current_app.config.get('FILES_URL')
             remove_webapp_brand = tenant.custom_config_dict.get('remove_webapp_brand', False)
-            replace_webapp_logo = f'{base_url}/files/workspaces/{tenant.id}/webapp-logo' if tenant.custom_config_dict['replace_webapp_logo'] else None
+            replace_webapp_logo = f'{base_url}/files/workspaces/{tenant.id}/webapp-logo' if tenant.custom_config_dict.get('replace_webapp_logo') else None
             self.custom_config = {
                 'remove_webapp_brand': remove_webapp_brand,
                 'replace_webapp_logo': replace_webapp_logo,
diff --git a/api/models/account.py b/api/models/account.py
index 2e2c831ded..5a86b4f8e0 100644
--- a/api/models/account.py
+++ b/api/models/account.py
@@ -127,7 +127,7 @@ class Tenant(db.Model):
     
     @property
     def custom_config_dict(self) -> dict:
-        return json.loads(self.custom_config) if self.custom_config else None
+        return json.loads(self.custom_config) if self.custom_config else {}
     
     @custom_config_dict.setter
     def custom_config_dict(self, value: dict):
diff --git a/web/i18n/lang/custom.en.ts b/web/i18n/lang/custom.en.ts
index 5e7f8bbf96..2d931a8da2 100644
--- a/web/i18n/lang/custom.en.ts
+++ b/web/i18n/lang/custom.en.ts
@@ -5,7 +5,7 @@ const translation = {
     suffix: 'customize your brand.',
   },
   webapp: {
-    title: 'Customize web app brand',
+    title: 'Customize WebApp brand',
     removeBrand: 'Remove Powered by Dify',
     changeLogo: 'Change Powered by Brand Image',
     changeLogoTip: 'SVG or PNG format with a minimum size of 40x40px',
diff --git a/web/i18n/lang/custom.zh.ts b/web/i18n/lang/custom.zh.ts
index 9910e0fa61..f8813831a3 100644
--- a/web/i18n/lang/custom.zh.ts
+++ b/web/i18n/lang/custom.zh.ts
@@ -5,7 +5,7 @@ const translation = {
     suffix: '定制您的品牌。',
   },
   webapp: {
-    title: '定制 web app 品牌',
+    title: '定制 WebApp 品牌',
     removeBrand: '移除 Powered by Dify',
     changeLogo: '更改 Powered by Brand 图片',
     changeLogoTip: 'SVG 或 PNG 格式，最小尺寸为 40x40px',