diff --git a/src/components/article/ArticleCard.tsx b/src/components/article/ArticleCard.tsx
index 9447352..9cdeaab 100644
--- a/src/components/article/ArticleCard.tsx
+++ b/src/components/article/ArticleCard.tsx
@@ -1,7 +1,7 @@
 import { NDKEvent, nip19 } from "@nostr-dev-kit/ndk";
 import { useProfile } from "../../hooks/useProfile";
 import { useUIStore } from "../../stores/ui";
-import { shortenPubkey } from "../../lib/utils";
+import { shortenPubkey, profileName } from "../../lib/utils";
 
 function getTag(event: NDKEvent, name: string): string {
   return event.tags.find((t) => t[0] === name)?.[1] ?? "";
@@ -32,7 +32,7 @@ export function ArticleCard({ event }: { event: NDKEvent }) {
   const publishedAt = parseInt(getTag(event, "published_at")) || event.created_at || null;
   const naddr = buildNaddr(event);
 
-  const authorName = profile?.displayName || profile?.name || shortenPubkey(event.pubkey);
+  const authorName = profileName(profile, shortenPubkey(event.pubkey));
   const date = publishedAt
     ? new Date(publishedAt * 1000).toLocaleDateString(undefined, { year: "numeric", month: "short", day: "numeric" })
     : null;
diff --git a/src/components/article/ArticleView.tsx b/src/components/article/ArticleView.tsx
index 268a36f..a0512be 100644
--- a/src/components/article/ArticleView.tsx
+++ b/src/components/article/ArticleView.tsx
@@ -8,6 +8,7 @@ import { useBookmarkStore } from "../../stores/bookmark";
 import { fetchArticle, publishReaction, publishRepost, publishNote } from "../../lib/nostr";
 import { nip19 } from "@nostr-dev-kit/ndk";
 import { useProfile } from "../../hooks/useProfile";
+import { profileName } from "../../lib/utils";
 import { ZapModal } from "../zap/ZapModal";
 
 // ── Types ────────────────────────────────────────────────────────────────────
@@ -33,7 +34,7 @@ function getTags(event: NDKEvent, name: string): string[] {
 function AuthorRow({ pubkey, publishedAt, readingTime }: { pubkey: string; publishedAt: number | null; readingTime?: number }) {
   const { openProfile } = useUIStore();
   const profile = useProfile(pubkey);
-  const name = profile?.displayName || profile?.name || pubkey.slice(0, 12) + "…";
+  const name = profileName(profile, pubkey.slice(0, 12) + "…");
   const date = publishedAt
     ? new Date(publishedAt * 1000).toLocaleDateString(undefined, { year: "numeric", month: "long", day: "numeric" })
     : null;
@@ -122,7 +123,7 @@ export function ArticleView() {
   const articleTags = event ? getTags(event, "t") : [];
   const authorPubkey = event?.pubkey ?? "";
   const authorProfile = useProfile(authorPubkey);
-  const authorName = authorProfile?.displayName || authorProfile?.name || authorPubkey.slice(0, 12) + "…";
+  const authorName = profileName(authorProfile, authorPubkey.slice(0, 12) + "…");
 
   const bodyHtml = event?.content ? renderMarkdown(event.content) : "";
   const wordCount = event?.content?.trim().split(/\s+/).length ?? 0;
diff --git a/src/components/dm/DMView.tsx b/src/components/dm/DMView.tsx
index 2ac4525..3ade4ee 100644
--- a/src/components/dm/DMView.tsx
+++ b/src/components/dm/DMView.tsx
@@ -5,7 +5,7 @@ import { useUIStore } from "../../stores/ui";
 import { useNotificationsStore } from "../../stores/notifications";
 import { fetchDMConversations, fetchDMThread, sendDM, decryptDM, getNDK } from "../../lib/nostr";
 import { useProfile } from "../../hooks/useProfile";
-import { timeAgo, shortenPubkey } from "../../lib/utils";
+import { timeAgo, shortenPubkey, profileName } from "../../lib/utils";
 
 // ── Helpers ──────────────────────────────────────────────────────────────────
 
@@ -45,7 +45,7 @@ function ConvRow({
   onSelect: () => void;
 }) {
   const profile = useProfile(partnerPubkey);
-  const name = profile?.displayName || profile?.name || shortenPubkey(partnerPubkey);
+  const name = profileName(profile, shortenPubkey(partnerPubkey));
   const time = lastEvent.created_at ? timeAgo(lastEvent.created_at) : "";
 
   return (
@@ -126,7 +126,7 @@ function ThreadPanel({
 }) {
   const { openProfile } = useUIStore();
   const profile = useProfile(partnerPubkey);
-  const name = profile?.displayName || profile?.name || shortenPubkey(partnerPubkey);
+  const name = profileName(profile, shortenPubkey(partnerPubkey));
 
   const [messages, setMessages] = useState<NDKEvent[]>([]);
   const [loading, setLoading] = useState(true);
diff --git a/src/components/feed/ComposeBox.tsx b/src/components/feed/ComposeBox.tsx
index 3b2e9fd..6529dda 100644
--- a/src/components/feed/ComposeBox.tsx
+++ b/src/components/feed/ComposeBox.tsx
@@ -4,7 +4,7 @@ import { uploadImage, uploadBytes } from "../../lib/upload";
 import { useAutoResize } from "../../hooks/useAutoResize";
 import { useUserStore } from "../../stores/user";
 import { useFeedStore } from "../../stores/feed";
-import { shortenPubkey } from "../../lib/utils";
+import { shortenPubkey, profileName } from "../../lib/utils";
 import { open } from "@tauri-apps/plugin-dialog";
 import { readFile } from "@tauri-apps/plugin-fs";
 import { EmojiPicker } from "../shared/EmojiPicker";
@@ -25,8 +25,8 @@ export function ComposeBox({ onPublished, onNoteInjected }: { onPublished?: () =
   const textareaRef = useRef<HTMLTextAreaElement>(null);
 
   const { profile, npub } = useUserStore();
-  const avatar = profile?.picture;
-  const name = profile?.displayName || profile?.name || (npub ? shortenPubkey(npub) : "");
+  const avatar = typeof profile?.picture === "string" ? profile.picture : undefined;
+  const name = profileName(profile, npub ? shortenPubkey(npub) : "");
 
   // Auto-save draft with debounce
   useEffect(() => {
diff --git a/src/components/feed/NoteActions.tsx b/src/components/feed/NoteActions.tsx
index 3307e15..fb967cc 100644
--- a/src/components/feed/NoteActions.tsx
+++ b/src/components/feed/NoteActions.tsx
@@ -7,6 +7,7 @@ import { useZapCount } from "../../hooks/useZapCount";
 import { useUserStore } from "../../stores/user";
 import { useBookmarkStore } from "../../stores/bookmark";
 import { publishReaction, publishRepost } from "../../lib/nostr";
+import { profileName } from "../../lib/utils";
 import { ZapModal } from "../zap/ZapModal";
 import { QuoteModal } from "./QuoteModal";
 
@@ -20,8 +21,8 @@ interface NoteActionsProps {
 
 export function NoteActions({ event, onReplyToggle, showReply }: NoteActionsProps) {
   const profile = useProfile(event.pubkey);
-  const name = profile?.displayName || profile?.name || event.pubkey.slice(0, 8) + "…";
-  const avatar = profile?.picture;
+  const name = profileName(profile, event.pubkey.slice(0, 8) + "…");
+  const avatar = typeof profile?.picture === "string" ? profile.picture : undefined;
   const { loggedIn } = useUserStore();
   const { bookmarkedIds, addBookmark, removeBookmark } = useBookmarkStore();
   const isBookmarked = bookmarkedIds.includes(event.id!);
diff --git a/src/components/feed/NoteCard.tsx b/src/components/feed/NoteCard.tsx
index 1b640fc..e637671 100644
--- a/src/components/feed/NoteCard.tsx
+++ b/src/components/feed/NoteCard.tsx
@@ -20,15 +20,17 @@ interface NoteCardProps {
 
 function ParentAuthorName({ pubkey }: { pubkey: string }) {
   const profile = useProfile(pubkey);
-  const name = profile?.displayName || profile?.name || pubkey.slice(0, 8) + "…";
+  const raw = profile?.displayName || profile?.name;
+  const name = (typeof raw === "string" ? raw : null) || pubkey.slice(0, 8) + "…";
   return <span className="text-accent">@{name}</span>;
 }
 
 export function NoteCard({ event, focused, onReplyInThread }: NoteCardProps) {
   const profile = useProfile(event.pubkey);
-  const name = profile?.displayName || profile?.name || shortenPubkey(event.pubkey);
+  const rawName = profile?.displayName || profile?.name;
+  const name = (typeof rawName === "string" ? rawName : null) || shortenPubkey(event.pubkey);
   const avatar = profile?.picture;
-  const nip05 = profile?.nip05;
+  const nip05 = typeof profile?.nip05 === "string" ? profile.nip05 : null;
   const verified = useNip05Verified(event.pubkey, nip05);
   const time = event.created_at ? timeAgo(event.created_at) : "";
 
diff --git a/src/components/feed/NoteContent.tsx b/src/components/feed/NoteContent.tsx
index dd5e776..19b5d72 100644
--- a/src/components/feed/NoteContent.tsx
+++ b/src/components/feed/NoteContent.tsx
@@ -122,7 +122,8 @@ function QuotePreview({ eventId }: { eventId: string }) {
 
   if (!event) return null;
 
-  const name = profile?.displayName || profile?.name || shortenPubkey(event.pubkey);
+  const rawName = profile?.displayName || profile?.name;
+  const name = (typeof rawName === "string" ? rawName : null) || shortenPubkey(event.pubkey);
   const preview = event.content.slice(0, 160) + (event.content.length > 160 ? "…" : "");
 
   return (
diff --git a/src/components/feed/TextSegments.tsx b/src/components/feed/TextSegments.tsx
index 043ddc5..1044db9 100644
--- a/src/components/feed/TextSegments.tsx
+++ b/src/components/feed/TextSegments.tsx
@@ -45,7 +45,8 @@ export function tryOpenNostrEntity(raw: string): boolean {
 export function MentionName({ pubkey, fallback }: { pubkey?: string; fallback: string }) {
   const profile = useProfile(pubkey ?? "");
   if (!pubkey) return <>{fallback}</>;
-  const name = profile?.displayName || profile?.name;
+  const raw = profile?.displayName || profile?.name;
+  const name = typeof raw === "string" ? raw : null;
   return <>{name || fallback}</>;
 }
 
@@ -65,7 +66,7 @@ export function renderTextSegments(
   segments.forEach((seg, i) => {
     switch (seg.type) {
       case "text":
-        elements.push(<span key={i}>{seg.value}</span>);
+        elements.push(<span key={i}>{typeof seg.value === "string" ? seg.value : String(seg.value)}</span>);
         break;
       case "link":
         elements.push(
@@ -79,7 +80,7 @@ export function renderTextSegments(
               if (tryHandleUrlInternally(seg.value)) e.preventDefault();
             }}
           >
-            {seg.display}
+            {typeof seg.display === "string" ? seg.display : String(seg.display)}
           </a>
         );
         break;
@@ -91,8 +92,8 @@ export function renderTextSegments(
             onClick={(e) => { e.stopPropagation(); tryOpenNostrEntity(seg.value); }}
           >
             @{resolveMentions
-              ? <MentionName pubkey={seg.mentionPubkey} fallback={seg.display ?? seg.value.slice(0, 12) + "…"} />
-              : seg.display}
+              ? <MentionName pubkey={seg.mentionPubkey} fallback={String(seg.display ?? seg.value).slice(0, 12) + "…"} />
+              : String(seg.display ?? seg.value)}
           </span>
         );
         break;
@@ -103,7 +104,7 @@ export function renderTextSegments(
             className="text-accent/80 cursor-pointer hover:text-accent"
             onClick={(e) => { e.stopPropagation(); openHashtag(seg.value); }}
           >
-            {seg.display}
+            {String(seg.display ?? seg.value)}
           </span>
         );
         break;
diff --git a/src/components/follows/FollowsView.tsx b/src/components/follows/FollowsView.tsx
index b8ee16c..1cdc496 100644
--- a/src/components/follows/FollowsView.tsx
+++ b/src/components/follows/FollowsView.tsx
@@ -6,7 +6,7 @@ import { useProfile } from "../../hooks/useProfile";
 import { useNip05Verified } from "../../hooks/useNip05Verified";
 import { fetchFollowers, ensureConnected } from "../../lib/nostr";
 import { dbLoadFollowers, dbSaveFollowers } from "../../lib/db";
-import { shortenPubkey } from "../../lib/utils";
+import { shortenPubkey, profileName } from "../../lib/utils";
 
 function FollowRow({
   pubkey,
@@ -16,9 +16,9 @@ function FollowRow({
   followsYou?: boolean;
 }) {
   const profile = useProfile(pubkey);
-  const name = profile?.displayName || profile?.name || shortenPubkey(pubkey);
-  const avatar = profile?.picture;
-  const nip05 = profile?.nip05;
+  const name = profileName(profile, shortenPubkey(pubkey));
+  const avatar = typeof profile?.picture === "string" ? profile.picture : undefined;
+  const nip05 = typeof profile?.nip05 === "string" ? profile.nip05 : undefined;
   const verified = useNip05Verified(pubkey, nip05);
 
   const { follows, follow, unfollow, pubkey: ownPubkey } = useUserStore();
diff --git a/src/components/profile/EditProfileForm.tsx b/src/components/profile/EditProfileForm.tsx
index e9d0ce2..89ac3c8 100644
--- a/src/components/profile/EditProfileForm.tsx
+++ b/src/components/profile/EditProfileForm.tsx
@@ -7,14 +7,15 @@ import { Nip05Field } from "./Nip05Field";
 
 export function EditProfileForm({ pubkey, onSaved }: { pubkey: string; onSaved: () => void }) {
   const { profile, fetchOwnProfile } = useUserStore();
-  const [name, setName] = useState(profile?.name || "");
-  const [displayName, setDisplayName] = useState(profile?.displayName || "");
-  const [about, setAbout] = useState(profile?.about || "");
-  const [picture, setPicture] = useState(profile?.picture || "");
-  const [banner, setBanner] = useState(profile?.banner || "");
-  const [website, setWebsite] = useState(profile?.website || "");
-  const [nip05, setNip05] = useState(profile?.nip05 || "");
-  const [lud16, setLud16] = useState(profile?.lud16 || "");
+  const safeStr = (v: unknown) => (typeof v === "string" ? v : "");
+  const [name, setName] = useState(safeStr(profile?.name));
+  const [displayName, setDisplayName] = useState(safeStr(profile?.displayName));
+  const [about, setAbout] = useState(safeStr(profile?.about));
+  const [picture, setPicture] = useState(safeStr(profile?.picture));
+  const [banner, setBanner] = useState(safeStr(profile?.banner));
+  const [website, setWebsite] = useState(safeStr(profile?.website));
+  const [nip05, setNip05] = useState(safeStr(profile?.nip05));
+  const [lud16, setLud16] = useState(safeStr(profile?.lud16));
   const [saving, setSaving] = useState(false);
   const [error, setError] = useState<string | null>(null);
   const [saved, setSaved] = useState(false);
diff --git a/src/components/profile/ProfileView.tsx b/src/components/profile/ProfileView.tsx
index 603829c..778ddac 100644
--- a/src/components/profile/ProfileView.tsx
+++ b/src/components/profile/ProfileView.tsx
@@ -6,7 +6,7 @@ import { useMuteStore } from "../../stores/mute";
 import { useProfile } from "../../hooks/useProfile";
 import { useReputation } from "../../hooks/useReputation";
 import { fetchUserNotesNIP65, fetchAuthorArticles, getNDK } from "../../lib/nostr";
-import { shortenPubkey } from "../../lib/utils";
+import { shortenPubkey, profileName } from "../../lib/utils";
 import { NoteCard } from "../feed/NoteCard";
 import { ArticleCard } from "../article/ArticleCard";
 import { ZapModal } from "../zap/ZapModal";
@@ -17,7 +17,7 @@ import { ProfileMediaGallery } from "./ProfileMediaGallery";
 function TopFollowerAvatar({ pubkey }: { pubkey: string }) {
   const profile = useProfile(pubkey);
   const { openProfile } = useUIStore();
-  const name = profile?.displayName || profile?.name || pubkey.slice(0, 8) + "…";
+  const name = profileName(profile, pubkey.slice(0, 8) + "…");
 
   return (
     <button
@@ -85,12 +85,12 @@ export function ProfileView() {
     }
   };
 
-  const name = profile?.displayName || profile?.name || shortenPubkey(pubkey);
-  const avatar = profile?.picture;
-  const about = profile?.about;
-  const nip05 = profile?.nip05;
-  const website = profile?.website;
-  const lud16 = profile?.lud16;
+  const name = profileName(profile, shortenPubkey(pubkey));
+  const avatar = typeof profile?.picture === "string" ? profile.picture : undefined;
+  const about = typeof profile?.about === "string" ? profile.about : undefined;
+  const nip05 = typeof profile?.nip05 === "string" ? profile.nip05 : undefined;
+  const website = typeof profile?.website === "string" ? profile.website : undefined;
+  const lud16 = typeof profile?.lud16 === "string" ? profile.lud16 : undefined;
 
   useEffect(() => {
     let cancelled = false;
diff --git a/src/components/thread/AncestorChain.tsx b/src/components/thread/AncestorChain.tsx
index 65a339c..1a95a27 100644
--- a/src/components/thread/AncestorChain.tsx
+++ b/src/components/thread/AncestorChain.tsx
@@ -1,12 +1,12 @@
 import { NDKEvent } from "@nostr-dev-kit/ndk";
 import { useProfile } from "../../hooks/useProfile";
 import { useUIStore } from "../../stores/ui";
-import { shortenPubkey, timeAgo } from "../../lib/utils";
+import { shortenPubkey, timeAgo, profileName } from "../../lib/utils";
 
 function AncestorCard({ event }: { event: NDKEvent }) {
   const profile = useProfile(event.pubkey);
-  const name = profile?.displayName || profile?.name || shortenPubkey(event.pubkey);
-  const avatar = profile?.picture;
+  const name = profileName(profile, shortenPubkey(event.pubkey));
+  const avatar = typeof profile?.picture === "string" ? profile.picture : undefined;
   const time = event.created_at ? timeAgo(event.created_at) : "";
   const { openThread } = useUIStore();
 
diff --git a/src/components/thread/ThreadNode.tsx b/src/components/thread/ThreadNode.tsx
index deea5b2..244f778 100644
--- a/src/components/thread/ThreadNode.tsx
+++ b/src/components/thread/ThreadNode.tsx
@@ -4,7 +4,7 @@ import type { ThreadNode as ThreadNodeType } from "../../lib/threadTree";
 import { NoteCard } from "../feed/NoteCard";
 import { publishReply } from "../../lib/nostr";
 import { useProfile } from "../../hooks/useProfile";
-import { shortenPubkey } from "../../lib/utils";
+import { shortenPubkey, profileName } from "../../lib/utils";
 import { EmojiPicker } from "../shared/EmojiPicker";
 import { useAutoResize } from "../../hooks/useAutoResize";
 
@@ -26,7 +26,7 @@ function InlineThreadReply({ replyTo, rootEvent, onPublished }: {
   onPublished: (reply: NDKEvent) => void;
 }) {
   const profile = useProfile(replyTo.pubkey);
-  const name = profile?.displayName || profile?.name || shortenPubkey(replyTo.pubkey);
+  const name = profileName(profile, shortenPubkey(replyTo.pubkey));
   const [text, setText] = useState("");
   const [replying, setReplying] = useState(false);
   const [sent, setSent] = useState(false);
diff --git a/src/components/zap/ZapHistoryView.tsx b/src/components/zap/ZapHistoryView.tsx
index 185b71e..63313f0 100644
--- a/src/components/zap/ZapHistoryView.tsx
+++ b/src/components/zap/ZapHistoryView.tsx
@@ -4,7 +4,7 @@ import { useUserStore } from "../../stores/user";
 import { useUIStore } from "../../stores/ui";
 import { fetchZapsReceived, fetchZapsSent, fetchNoteById } from "../../lib/nostr";
 import { useProfile } from "../../hooks/useProfile";
-import { timeAgo, shortenPubkey } from "../../lib/utils";
+import { timeAgo, shortenPubkey, profileName } from "../../lib/utils";
 
 // ── Parsing helpers ──────────────────────────────────────────────────────────
 
@@ -53,9 +53,9 @@ function ZapRow({
   const { openProfile, openThread } = useUIStore();
   const profile = useProfile(pubkey ?? "");
   const name = pubkey
-    ? profile?.displayName || profile?.name || shortenPubkey(pubkey)
+    ? profileName(profile, shortenPubkey(pubkey))
     : "anonymous";
-  const avatar = profile?.picture;
+  const avatar = typeof profile?.picture === "string" ? profile.picture : undefined;
   const [notePreview, setNotePreview] = useState<string | null>(null);
   const [noteEvent, setNoteEvent] = useState<NDKEvent | null>(null);
   const [loadingNote, setLoadingNote] = useState(false);
diff --git a/src/lib/utils.ts b/src/lib/utils.ts
index ae887f0..49900ad 100644
--- a/src/lib/utils.ts
+++ b/src/lib/utils.ts
@@ -11,3 +11,9 @@ export function timeAgo(timestamp: number): string {
 export function shortenPubkey(pubkey: string): string {
   return pubkey.slice(0, 8) + "…" + pubkey.slice(-4);
 }
+
+/** Safely extract display name from a Nostr profile (handles non-string values from malformed profiles). */
+export function profileName(profile: any, fallback: string): string {
+  const raw = profile?.displayName || profile?.name;
+  return (typeof raw === "string" ? raw : null) || fallback;
+}
diff --git a/src/main.tsx b/src/main.tsx
index 1fdebd5..d8d1a20 100644
--- a/src/main.tsx
+++ b/src/main.tsx
@@ -1,15 +1,42 @@
 import "./lib/tauri-dev-mock"; // must be first — mocks Tauri invoke() in browser dev mode
-import { StrictMode } from "react";
+import { StrictMode, Component, type ReactNode } from "react";
 import { createRoot } from "react-dom/client";
 import App from "./App";
 import "./index.css";
 import { useUserStore } from "./stores/user";
 
+// Error boundary to catch React error #31 and show details instead of blank screen
+class ErrorBoundary extends Component<{ children: ReactNode }, { error: Error | null }> {
+  state: { error: Error | null } = { error: null };
+  static getDerivedStateFromError(error: Error) { return { error }; }
+  componentDidCatch(error: Error, info: React.ErrorInfo) {
+    console.error("[Vega] React error boundary caught:", error, info.componentStack);
+  }
+  render() {
+    if (this.state.error) {
+      return (
+        <div style={{ padding: 20, color: "#ff6b6b", fontFamily: "monospace", fontSize: 13 }}>
+          <h2>Vega crashed</h2>
+          <pre style={{ whiteSpace: "pre-wrap", wordBreak: "break-all" }}>
+            {this.state.error.message}
+          </pre>
+          <pre style={{ whiteSpace: "pre-wrap", wordBreak: "break-all", color: "#aaa", marginTop: 10 }}>
+            {this.state.error.stack}
+          </pre>
+        </div>
+      );
+    }
+    return this.props.children;
+  }
+}
+
 // Restore session — pubkey (read-only) or nsec via OS keychain
 useUserStore.getState().restoreSession();
 
 createRoot(document.getElementById("root") as HTMLElement).render(
   <StrictMode>
-    <App />
+    <ErrorBoundary>
+      <App />
+    </ErrorBoundary>
   </StrictMode>,
 );