diff --git a/README.md b/README.md
index cc89889..b366a9e 100644
--- a/README.md
+++ b/README.md
@@ -1,13 +1,13 @@
 # Bedolaga Cabinet - Web Interface
 
-Веб-интерфейс личного кабинета для VPN бота на базе [Remnawave Bedolaga Telegram Bot V3.0.0+](https://github.com/BEDOLAGA-DEV/remnawave-bedolaga-telegram-bot).
+Веб-интерфейс личного кабинета для VPN бота на базе [Remnawave Bedolaga Telegram Bot v3.33.0+](https://github.com/BEDOLAGA-DEV/remnawave-bedolaga-telegram-bot).
 
 React + Vite + TypeScript | Авторизация через Telegram | Мультиязычность (EN/RU) | Адаптивный дизайн
 
 ## Требования
 
 - Docker и Docker Compose
-- Запущенный backend бота с включенным Cabinet API
+- Запущенный backend бота с включенным Cabinet API, версия **v3.33.0 или новее** — авторизация кабинета использует deep-link эндпоинты (`/cabinet/auth/deeplink/*`), которых нет в более старых версиях. На старом боте кабинет не сможет авторизовать пользователей (залоченные теги вроде `:3` не подходят — используйте `:latest` или конкретный тег ≥ 3.33.0)
 - Обратный прокси (Caddy / Nginx / Traefik)
 
 ## Архитектура
diff --git a/src/api/branding.ts b/src/api/branding.ts
index e57a130..72d6ffc 100644
--- a/src/api/branding.ts
+++ b/src/api/branding.ts
@@ -1,4 +1,5 @@
 import apiClient from './client';
+import { isEndpointMissingError } from '../utils/api-error';
 import type { AnimationConfig } from '@/components/ui/backgrounds/types';
 import { DEFAULT_ANIMATION_CONFIG } from '@/components/ui/backgrounds/types';
 
@@ -36,6 +37,8 @@ export interface TelegramWidgetConfig {
   request_access: boolean;
   oidc_enabled: boolean;
   oidc_client_id: string;
+  /** The bot answered 404 on the config route — build older than v3.24.0. */
+  endpoint_missing?: boolean;
 }
 
 export interface OfflineConvGoal {
@@ -321,7 +324,7 @@ export const brandingApi = {
         '/cabinet/branding/telegram-widget',
       );
       return response.data;
-    } catch {
+    } catch (err) {
       return {
         bot_username: import.meta.env.VITE_TELEGRAM_BOT_USERNAME || '',
         size: 'large',
@@ -330,6 +333,7 @@ export const brandingApi = {
         request_access: true,
         oidc_enabled: false,
         oidc_client_id: '',
+        endpoint_missing: isEndpointMissingError(err),
       };
     }
   },
diff --git a/src/components/TelegramLoginButton.tsx b/src/components/TelegramLoginButton.tsx
index c31df2c..15dc748 100644
--- a/src/components/TelegramLoginButton.tsx
+++ b/src/components/TelegramLoginButton.tsx
@@ -9,6 +9,7 @@ import { useAuthStore } from '../store/auth';
 import { useNavigate } from 'react-router';
 import { getPendingCampaignSlug } from '../utils/campaign';
 import { copyToClipboard } from '../utils/clipboard';
+import { isEndpointMissingError } from '../utils/api-error';
 
 interface TelegramLoginButtonProps {
   referralCode?: string;
@@ -159,7 +160,6 @@ export default function TelegramLoginButton({ referralCode }: TelegramLoginButto
     isOIDC,
     widgetConfig?.oidc_client_id,
     widgetConfig?.request_access,
-    t,
     scriptLoaded,
     handleScriptFailed,
   ]);
@@ -330,8 +330,9 @@ export default function TelegramLoginButton({ referralCode }: TelegramLoginButto
         },
         (expires_in || 300) * 1000,
       );
-    } catch {
-      setDeepLinkError(t('common.error'));
+    } catch (err) {
+      // 404 = the deep-link auth routes don't exist on this bot build (< v3.33.0)
+      setDeepLinkError(t(isEndpointMissingError(err) ? 'auth.botOutdated' : 'common.error'));
     }
   }, [botUsername, loginWithDeepLink, navigate, t]);
 
@@ -421,9 +422,11 @@ export default function TelegramLoginButton({ referralCode }: TelegramLoginButto
   }, [deepLinkPolling, deepLinkToken, loginWithDeepLink, navigate, t]);
 
   if (!botUsername || botUsername === 'your_bot') {
+    // 404 on the config route = the bot build predates the cabinet endpoints,
+    // which reads as "not configured" but is actually a version mismatch (#345).
     return (
       <div className="py-4 text-center text-sm text-dark-400">
-        {t('auth.telegramNotConfigured')}
+        {t(widgetConfig?.endpoint_missing ? 'auth.botOutdated' : 'auth.telegramNotConfigured')}
       </div>
     );
   }
diff --git a/src/locales/en.json b/src/locales/en.json
index 6221861..92b8a93 100644
--- a/src/locales/en.json
+++ b/src/locales/en.json
@@ -201,6 +201,7 @@
     "telegramRetryFailed": "Authorization failed. Close the app and try again.",
     "telegramReopenHint": "If the problem persists, close and reopen the app",
     "telegramNotConfigured": "Telegram bot is not configured",
+    "botOutdated": "The bot version is not compatible with the cabinet. Update the bot to v3.33.0 or newer.",
     "telegramUnavailable": "Telegram login is temporarily unavailable",
     "authenticating": "Authenticating...",
     "orOpenInApp": "Or open the bot in the app",
diff --git a/src/locales/fa.json b/src/locales/fa.json
index 5142049..33372f7 100644
--- a/src/locales/fa.json
+++ b/src/locales/fa.json
@@ -193,6 +193,7 @@
     "telegramRetryFailed": "تایید هویت ناموفق بود. برنامه را ببندید و دوباره باز کنید.",
     "telegramReopenHint": "اگر مشکل ادامه دارد، برنامه را ببندید و دوباره باز کنید",
     "telegramNotConfigured": "ربات تلگرام پیکربندی نشده",
+    "botOutdated": "نسخهٔ ربات با کابینت سازگار نیست. ربات را به v3.33.0 یا جدیدتر به‌روزرسانی کنید.",
     "telegramUnavailable": "ورود از طریق تلگرام موقتاً در دسترس نیست",
     "authenticating": "در حال تایید هویت...",
     "orOpenInApp": "یا ربات را در برنامه باز کنید",
diff --git a/src/locales/ru.json b/src/locales/ru.json
index 32fc373..038aaa1 100644
--- a/src/locales/ru.json
+++ b/src/locales/ru.json
@@ -204,6 +204,7 @@
     "telegramRetryFailed": "Авторизация не удалась. Закройте приложение и откройте заново.",
     "telegramReopenHint": "Если проблема повторяется, закройте и откройте приложение заново",
     "telegramNotConfigured": "Telegram бот не настроен",
+    "botOutdated": "Версия бота несовместима с кабинетом. Обновите бота до v3.33.0 или новее.",
     "telegramUnavailable": "Вход через Telegram временно недоступен",
     "authenticating": "Авторизация...",
     "orOpenInApp": "Или откройте бота в приложении",
diff --git a/src/locales/zh.json b/src/locales/zh.json
index 356a5c3..c9cfb4a 100644
--- a/src/locales/zh.json
+++ b/src/locales/zh.json
@@ -193,6 +193,7 @@
     "telegramRetryFailed": "授权失败。请关闭应用后重新打开。",
     "telegramReopenHint": "如果问题持续存在，请关闭并重新打开应用",
     "telegramNotConfigured": "Telegram机器人未配置",
+    "botOutdated": "机器人版本与后台不兼容，请将机器人更新至 v3.33.0 或更高版本。",
     "telegramUnavailable": "Telegram登录暂时不可用",
     "authenticating": "正在验证...",
     "orOpenInApp": "或在应用中打开机器人",
diff --git a/src/utils/api-error.test.ts b/src/utils/api-error.test.ts
new file mode 100644
index 0000000..bb6c5bb
--- /dev/null
+++ b/src/utils/api-error.test.ts
@@ -0,0 +1,59 @@
+import { AxiosError, AxiosHeaders } from 'axios';
+import { describe, expect, it } from 'vitest';
+import { getApiErrorMessage, isEndpointMissingError } from './api-error';
+
+function axiosErrorWithStatus(status: number, detail?: unknown): AxiosError {
+  const headers = new AxiosHeaders();
+  const config = { headers };
+  return new AxiosError(
+    'Request failed',
+    'ERR_BAD_REQUEST',
+    config,
+    {},
+    {
+      status,
+      statusText: '',
+      headers,
+      config,
+      data: detail === undefined ? {} : { detail },
+    },
+  );
+}
+
+describe('isEndpointMissingError', () => {
+  it('returns true for an axios 404', () => {
+    expect(isEndpointMissingError(axiosErrorWithStatus(404))).toBe(true);
+  });
+
+  it('returns false for other axios statuses', () => {
+    expect(isEndpointMissingError(axiosErrorWithStatus(403))).toBe(false);
+    expect(isEndpointMissingError(axiosErrorWithStatus(500))).toBe(false);
+  });
+
+  it('returns false for non-axios errors', () => {
+    expect(isEndpointMissingError(new Error('boom'))).toBe(false);
+    expect(isEndpointMissingError(undefined)).toBe(false);
+    expect(isEndpointMissingError(null)).toBe(false);
+  });
+});
+
+describe('getApiErrorMessage', () => {
+  it('returns string detail from an axios error', () => {
+    expect(getApiErrorMessage(axiosErrorWithStatus(400, 'Code must not be empty'), 'fb')).toBe(
+      'Code must not be empty',
+    );
+  });
+
+  it('joins pydantic validation errors', () => {
+    const err = axiosErrorWithStatus(422, [
+      { loc: ['body', 'name'], msg: 'field required' },
+      { loc: ['body', 'days'], msg: 'must be positive' },
+    ]);
+    expect(getApiErrorMessage(err, 'fb')).toBe('name: field required; days: must be positive');
+  });
+
+  it('falls back for non-axios errors and missing detail', () => {
+    expect(getApiErrorMessage(new Error('boom'), 'fb')).toBe('fb');
+    expect(getApiErrorMessage(axiosErrorWithStatus(500), 'fb')).toBe('fb');
+  });
+});
diff --git a/src/utils/api-error.ts b/src/utils/api-error.ts
index b33e2ff..8e9f850 100644
--- a/src/utils/api-error.ts
+++ b/src/utils/api-error.ts
@@ -1,5 +1,15 @@
 import axios from 'axios';
 
+/**
+ * True when the backend answered 404 on the route itself — for cabinet
+ * endpoints that means the bot build is too old to have them (e.g. the
+ * deep-link auth routes exist only since bot v3.33.0), as opposed to a
+ * missing entity inside a handler.
+ */
+export function isEndpointMissingError(err: unknown): boolean {
+  return axios.isAxiosError(err) && err.response?.status === 404;
+}
+
 export function getApiErrorMessage(err: unknown, fallback: string): string {
   if (axios.isAxiosError(err)) {
     const detail = err.response?.data?.detail;