diff --git a/linux.py b/linux.py
index 1c96d63..85e02f9 100644
--- a/linux.py
+++ b/linux.py
@@ -151,16 +151,16 @@ def _edit_config_dialog() -> None:
             done.set()
 
         def on_save() -> None:
+            from tkinter import messagebox
             merged = validate_config_form(widgets, DEFAULT_CONFIG, include_autostart=False)
             if isinstance(merged, str):
-                _show_error(merged)
+                messagebox.showerror("TG WS Proxy — Ошибка", merged, parent=root)
                 return
             save_config(merged)
             _config.update(merged)
             log.info("Config saved: %s", merged)
             _tray_icon.menu = _build_menu()
 
-            from tkinter import messagebox
             do_restart = messagebox.askyesno(
                 "Перезапустить?",
                 "Настройки сохранены.\n\nПерезапустить прокси сейчас?",
diff --git a/proxy/tg_ws_proxy.py b/proxy/tg_ws_proxy.py
index dc245dd..3c18d05 100644
--- a/proxy/tg_ws_proxy.py
+++ b/proxy/tg_ws_proxy.py
@@ -1043,7 +1043,7 @@ async def _run(stop_event: Optional[asyncio.Event] = None):
     log.info("=" * 60)
     log.info("  Telegram MTProto WS Bridge Proxy")
     log.info("  Listening on   %s:%d", proxy_config.host, proxy_config.port)
-    log.info("  Secret:        %s", "dd" + proxy_config.secret)
+    log.info("  Secret:        %s", proxy_config.secret)
     log.info("  Target DC IPs:")
     for dc in sorted(proxy_config.dc_redirects.keys()):
         ip = proxy_config.dc_redirects.get(dc)
diff --git a/ui/ctk_tray_ui.py b/ui/ctk_tray_ui.py
index 95e85fd..fd42efa 100644
--- a/ui/ctk_tray_ui.py
+++ b/ui/ctk_tray_ui.py
@@ -372,10 +372,18 @@ def validate_config_form(
     except ValueError as e:
         return str(e)
 
+    secret_val = widgets.secret_var.get().strip()
+    if len(secret_val) != 32:
+        return "Secret должен содержать ровно 32 hex-символа (16 байт)."
+    try:
+        bytes.fromhex(secret_val)
+    except ValueError:
+        return "Secret должен состоять только из hex-символов (0-9, a-f)."
+
     new_cfg: Dict[str, Any] = {
         "host": host_val,
         "port": port_val,
-        "secret": widgets.secret_var.get().strip(),
+        "secret": secret_val,
         "dc_ip": lines,
         "verbose": widgets.verbose_var.get(),
     }
diff --git a/windows.py b/windows.py
index d612bd0..22e490b 100644
--- a/windows.py
+++ b/windows.py
@@ -214,9 +214,10 @@ def _edit_config_dialog() -> None:
             done.set()
 
         def on_save() -> None:
+            from tkinter import messagebox
             merged = validate_config_form(widgets, DEFAULT_CONFIG, include_autostart=_supports_autostart())
             if isinstance(merged, str):
-                _show_error(merged)
+                messagebox.showerror("TG WS Proxy — Ошибка", merged, parent=root)
                 return
             save_config(merged)
             _config.update(merged)
@@ -225,7 +226,6 @@ def _edit_config_dialog() -> None:
                 set_autostart_enabled(bool(merged.get("autostart", False)))
             _tray_icon.menu = _build_menu()
 
-            from tkinter import messagebox
             do_restart = messagebox.askyesno(
                 "Перезапустить?",
                 "Настройки сохранены.\n\nПерезапустить прокси сейчас?",