diff --git a/web/api.py b/web/api.py
index 4c245f2..5ff0214 100644
--- a/web/api.py
+++ b/web/api.py
@@ -1228,7 +1228,15 @@ def patch_environment(project_id: str, env_id: int, body: EnvironmentPatch):
     if body.is_installed is not None:
         fields["is_installed"] = int(body.is_installed)
 
-    updated = models.update_environment(conn, env_id, **fields)
+    try:
+        updated = models.update_environment(conn, env_id, **fields)
+    except Exception as e:
+        conn.close()
+        if "UNIQUE constraint" in str(e):
+            raise HTTPException(409, f"Environment name already exists for this project")
+        if "KIN_SECRET_KEY" in str(e):
+            raise HTTPException(503, "Server misconfiguration: KIN_SECRET_KEY is not set. Contact admin.")
+        raise HTTPException(500, str(e))
 
     scan_task_id = None
     if body.is_installed is True and not was_installed:
diff --git a/web/frontend/src/views/ChatView.vue b/web/frontend/src/views/ChatView.vue
index 1ef0613..0d2b151 100644
--- a/web/frontend/src/views/ChatView.vue
+++ b/web/frontend/src/views/ChatView.vue
@@ -12,6 +12,7 @@ const input = ref('')
 const sending = ref(false)
 const loading = ref(true)
 const error = ref('')
+const consecutiveErrors = ref(0)
 const projectName = ref('')
 const messagesEl = ref<HTMLElement | null>(null)
 
@@ -37,8 +38,17 @@ function checkAndPoll() {
     try {
       const updated = await api.chatHistory(props.projectId)
       messages.value = updated
+      consecutiveErrors.value = 0
+      error.value = ''
       if (!hasRunningTasks(updated)) stopPoll()
-    } catch {}
+    } catch (e: any) {
+      consecutiveErrors.value++
+      console.warn(`[polling] ошибка #${consecutiveErrors.value}:`, e)
+      if (consecutiveErrors.value >= 3) {
+        error.value = 'Сервер недоступен. Проверьте подключение.'
+        stopPoll()
+      }
+    }
   }, 3000)
 }
 
@@ -46,6 +56,7 @@ async function load() {
   stopPoll()
   loading.value = true
   error.value = ''
+  consecutiveErrors.value = 0
   try {
     const [msgs, project] = await Promise.all([
       api.chatHistory(props.projectId),