diff --git a/src/features/authFiles/components/AuthFilesPrefixProxyEditorModal.tsx b/src/features/authFiles/components/AuthFilesPrefixProxyEditorModal.tsx
index 1cdf7fc..8e811c9 100644
--- a/src/features/authFiles/components/AuthFilesPrefixProxyEditorModal.tsx
+++ b/src/features/authFiles/components/AuthFilesPrefixProxyEditorModal.tsx
@@ -143,7 +143,7 @@ export function AuthFilesPrefixProxyEditorModal(props: AuthFilesPrefixProxyEdito
                   <textarea
                     className="input"
                     value={editor.headersText}
-                    placeholder='{"X-Custom-Header": "value"}'
+                    placeholder={t('auth_files.headers_placeholder')}
                     rows={4}
                     disabled={disableControls || editor.saving || !editor.json}
                     onChange={(e) => onChange('headersText', e.target.value)}
diff --git a/src/features/authFiles/hooks/useAuthFilesPrefixProxyEditor.ts b/src/features/authFiles/hooks/useAuthFilesPrefixProxyEditor.ts
index 2b961d6..a05bcdf 100644
--- a/src/features/authFiles/hooks/useAuthFilesPrefixProxyEditor.ts
+++ b/src/features/authFiles/hooks/useAuthFilesPrefixProxyEditor.ts
@@ -107,11 +107,16 @@ const buildPrefixProxyUpdatedText = (editor: PrefixProxyEditorState | null): str
   }
 
   if (editor.headersText.trim()) {
+    let parsedHeaders;
     try {
-      next.headers = JSON.parse(editor.headersText);
+      parsedHeaders = JSON.parse(editor.headersText);
     } catch {
-      // ignore or handle error
+      throw new Error('Invalid JSON format for Custom Headers. Must be an object.');
     }
+    if (!parsedHeaders || typeof parsedHeaders !== 'object' || Array.isArray(parsedHeaders)) {
+      throw new Error('Invalid JSON format for Custom Headers. Must be an object.');
+    }
+    next.headers = parsedHeaders;
   } else {
     delete next.headers;
   }
@@ -130,11 +135,17 @@ export function useAuthFilesPrefixProxyEditor(
 
   const [prefixProxyEditor, setPrefixProxyEditor] = useState<PrefixProxyEditorState | null>(null);
 
-  const prefixProxyUpdatedText = buildPrefixProxyUpdatedText(prefixProxyEditor);
+  let prefixProxyUpdatedText = '';
+  try {
+    prefixProxyUpdatedText = buildPrefixProxyUpdatedText(prefixProxyEditor);
+  } catch {
+    // Catch JSON parsing errors during render so the UI doesn't crash.
+  }
+
   const prefixProxyDirty =
     Boolean(prefixProxyEditor?.json) &&
     Boolean(prefixProxyEditor?.originalText) &&
-    prefixProxyUpdatedText !== prefixProxyEditor?.originalText;
+    (prefixProxyUpdatedText === '' || prefixProxyUpdatedText !== prefixProxyEditor?.originalText);
 
   const closePrefixProxyEditor = () => {
     setPrefixProxyEditor(null);
@@ -285,7 +296,15 @@ export function useAuthFilesPrefixProxyEditor(
     if (!prefixProxyDirty) return;
 
     const name = prefixProxyEditor.fileName;
-    const payload = prefixProxyUpdatedText;
+    let payload = '';
+    try {
+      payload = buildPrefixProxyUpdatedText(prefixProxyEditor);
+    } catch (err: unknown) {
+      const errorMessage = err instanceof Error ? err.message : 'Invalid format';
+      showNotification(errorMessage, 'error');
+      return;
+    }
+
     const fileSize = new Blob([payload]).size;
     if (fileSize > MAX_AUTH_FILE_SIZE) {
       showNotification(
diff --git a/src/i18n/locales/en.json b/src/i18n/locales/en.json
index ce56efd..0a97499 100644
--- a/src/i18n/locales/en.json
+++ b/src/i18n/locales/en.json
@@ -599,6 +599,7 @@
     "note_display": "Note",
     "headers_label": "Custom Headers (headers)",
     "headers_placeholder": "{\n  \"Header-Name\": \"value\"\n}",
+    "headers_hint": "Enter custom HTTP headers as a JSON object, e.g., {\"X-My-Header\": \"value\"}",
     "prefix_proxy_invalid_json": "This auth file is not a JSON object, so fields cannot be edited.",
     "prefix_proxy_saved_success": "Updated auth file \"{{name}}\" successfully",
     "quota_refresh_success": "Quota refreshed for \"{{name}}\"",
diff --git a/src/i18n/locales/zh-CN.json b/src/i18n/locales/zh-CN.json
index dc9135b..48bcd16 100644
--- a/src/i18n/locales/zh-CN.json
+++ b/src/i18n/locales/zh-CN.json
@@ -599,6 +599,7 @@
     "note_display": "备注",
     "headers_label": "自定义请求头（headers）",
     "headers_placeholder": "{\n  \"Header-Name\": \"value\"\n}",
+    "headers_hint": "以 JSON 对象格式输入自定义 HTTP 请求头，例如：{\"X-My-Header\": \"value\"}",
     "prefix_proxy_invalid_json": "该认证文件不是 JSON 对象，无法编辑字段。",
     "prefix_proxy_saved_success": "已更新认证文件 \"{{name}}\"",
     "quota_refresh_success": "已刷新 \"{{name}}\" 的额度",