diff --git a/src/torq/api/routes.py b/src/torq/api/routes.py
index 1a775c5..beab88e 100644
--- a/src/torq/api/routes.py
+++ b/src/torq/api/routes.py
@@ -5,7 +5,7 @@
 from datetime import datetime, timezone
 from fastapi import APIRouter, HTTPException, Request
 from fastapi.responses import FileResponse, StreamingResponse
-from pydantic import BaseModel
+from pydantic import BaseModel, Field
 
 from torq.config import settings
 from torq.db import models
@@ -19,13 +19,13 @@
 
 
 class MachineIn(BaseModel):
-    id: str
-    model: str
-    location: str
+    id: str = Field(max_length=100)
+    model: str = Field(max_length=200)
+    location: str = Field(max_length=200)
 
 
 class FaultIn(BaseModel):
-    fault_code: str
+    fault_code: str = Field(min_length=1, max_length=50)
     machine: str = ""
     context: str = ""
     translate: bool = True
diff --git a/src/torq/config.py b/src/torq/config.py
index 0abbc6d..fa7cc73 100644
--- a/src/torq/config.py
+++ b/src/torq/config.py
@@ -29,17 +29,12 @@ def _ensure_llm_key(self):
         if not self.llm_api_key:
             self.llm_api_key = os.environ.get("OPENAI_API_KEY", "")
         if not self.llm_api_key:
-            print("=" * 60)
-            print("  FATAL: No LLM API key found.")
-            print()
-            print("  Set LLM_API_KEY or OPENAI_API_KEY in your .env file")
-            print("  or export it as an environment variable.")
-            print()
-            print("  Example:")
-            print("    LLM_API_KEY=sk-...  # DeepSeek (default)")
-            print("    OPENAI_API_KEY=sk-...  # OpenAI-compatible")
-            print("=" * 60)
-            sys.exit(1)
+            import logging
+            logging.warning(
+                "No LLM API key found. "
+                "Set LLM_API_KEY or OPENAI_API_KEY in your .env file. "
+                "LLM-dependent features (diagnosis, translation) will fall back."
+            )
         return self
 
     # Vector DB (Qdrant)
diff --git a/src/torq/dispatch/routing.py b/src/torq/dispatch/routing.py
index 822406c..3c5fa00 100644
--- a/src/torq/dispatch/routing.py
+++ b/src/torq/dispatch/routing.py
@@ -11,7 +11,10 @@ def _load_roster(shifts_file: Path | None = None) -> list[dict]:
     shifts_file = shifts_file or settings.shifts_file
     if not shifts_file.exists():
         return []
-    return json.loads(shifts_file.read_text(encoding="utf-8"))
+    try:
+        return json.loads(shifts_file.read_text(encoding="utf-8"))
+    except (OSError, json.JSONDecodeError):
+        return []
 
 
 def choose_technician(wo: WorkOrder, roster: list[dict] | None = None) -> dict | None:
diff --git a/web/src/ErrorBoundary.jsx b/web/src/ErrorBoundary.jsx
new file mode 100644
index 0000000..68ce9df
--- /dev/null
+++ b/web/src/ErrorBoundary.jsx
@@ -0,0 +1,25 @@
+import { Component } from "react";
+
+export default class ErrorBoundary extends Component {
+  constructor(props) {
+    super(props);
+    this.state = { error: null };
+  }
+
+  static getDerivedStateFromError(error) {
+    return { error };
+  }
+
+  render() {
+    if (this.state.error) {
+      return (
+        <div className="errorBoundary">
+          <h1>Something went wrong</h1>
+          <pre>{this.state.error.message}</pre>
+          <button onClick={() => window.location.reload()}>Reload page</button>
+        </div>
+      );
+    }
+    return this.props.children;
+  }
+}
diff --git a/web/src/main.jsx b/web/src/main.jsx
index 46f15cf..efa8804 100644
--- a/web/src/main.jsx
+++ b/web/src/main.jsx
@@ -2,6 +2,7 @@ import React from "react";
 import ReactDOM from "react-dom/client";
 import { BrowserRouter } from "react-router-dom";
 import App from "./App.jsx";
+import ErrorBoundary from "./ErrorBoundary.jsx";
 import { I18nProvider } from "./i18n";
 import { ToastProvider } from "./toast.jsx";
 import "./styles.css";
@@ -11,7 +12,9 @@ ReactDOM.createRoot(document.getElementById("root")).render(
     <BrowserRouter>
       <I18nProvider>
         <ToastProvider>
-          <App />
+          <ErrorBoundary>
+            <App />
+          </ErrorBoundary>
         </ToastProvider>
       </I18nProvider>
     </BrowserRouter>
diff --git a/web/src/pages/Dashboard.jsx b/web/src/pages/Dashboard.jsx
index 2f27a01..3166d4f 100644
--- a/web/src/pages/Dashboard.jsx
+++ b/web/src/pages/Dashboard.jsx
@@ -217,6 +217,7 @@ function ActivityLog() {
         /* ignore malformed frame */
       }
     });
+    es.onerror = () => setEntries((prev) => [...prev, { type: "disconnected", detail: "SSE lost" }]);
     return () => {
       alive = false;
       es.close();
@@ -570,10 +571,14 @@ export default function Dashboard() {
   const [machineDetail, setMachineDetail] = useState(null);
   const [busy, setBusy] = useState(false);
   const [loading, setLoading] = useState(true);
+  const [errored, setErrored] = useState(false);
   const [statusFilter, setStatusFilter] = useState("");
   const [searchQuery, setSearchQuery] = useState("");
 
+  const inflight = useRef(false);
   const load = useCallback(async () => {
+    if (inflight.current) return;
+    inflight.current = true;
     try {
       const [m, p, a, ev, trend, fpm] = await Promise.all([
         api.getMetrics(),
@@ -590,8 +595,12 @@ export default function Dashboard() {
       setTrendData(trend);
       setFpmData(fpm);
       setLoading(false);
+      setErrored(false);
     } catch (e) {
       setLoading(false);
+      setErrored(true);
+    } finally {
+      inflight.current = false;
     }
   }, []);
 
@@ -657,6 +666,8 @@ export default function Dashboard() {
           <p className={styles.sub}>{t("dashboard.subtitle")}</p>
         </header>
 
+        {errored && <div className="dashboardError">Could not load data — check connection</div>}
+
         <section className={styles.tiles}>
           {loading ? (
             <>
diff --git a/web/src/styles.css b/web/src/styles.css
index 2130c1c..d948673 100644
--- a/web/src/styles.css
+++ b/web/src/styles.css
@@ -182,3 +182,37 @@ body {
   animation: shimmer 1.5s ease-in-out infinite;
   border-radius: 8px;
 }
+
+/* ── Error boundary ── */
+
+.errorBoundary {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  min-height: 100vh;
+  padding: 2rem;
+  text-align: center;
+}
+.errorBoundary pre {
+  color: var(--text-secondary, #666);
+  max-width: 600px;
+  overflow-x: auto;
+}
+.errorBoundary button {
+  margin-top: 1rem;
+  padding: 0.6rem 1.5rem;
+  background: var(--accent, #2563eb);
+  color: #fff;
+  border: none;
+  border-radius: 6px;
+  cursor: pointer;
+}
+
+/* ── Dashboard errored state ── */
+
+.dashboardError {
+  text-align: center;
+  padding: 2rem;
+  color: var(--text-secondary, #666);
+}