diff --git a/packages/app/src/Components/Event/Note/ClientTag.tsx b/packages/app/src/Components/Event/Note/ClientTag.tsx
index 8ecd486c..64e9d6f0 100644
--- a/packages/app/src/Components/Event/Note/ClientTag.tsx
+++ b/packages/app/src/Components/Event/Note/ClientTag.tsx
@@ -5,7 +5,7 @@ import { Link } from "react-router-dom";
 export function ClientTag({ ev }: { ev: TaggedNostrEvent }) {
   const tag = ev.tags.find(a => a[0] === "client");
   if (!tag) return;
-  const link = tag[2] && tag[2].includes(":") ? NostrLink.fromTag(["a", tag[2]]) : undefined;
+  const link = tag[2] && tag[2].includes(":") ? NostrLink.tryFromTag(["a", tag[2]]) : undefined;
   return (
     <span className="text-xs text-gray-light">
       {" "}
diff --git a/packages/system/src/nostr-link.ts b/packages/system/src/nostr-link.ts
index e4e22089..aead391c 100644
--- a/packages/system/src/nostr-link.ts
+++ b/packages/system/src/nostr-link.ts
@@ -235,16 +235,30 @@ export class NostrLink implements ToNostrEventTag {
       }
       case "A": {
         const [kind, author, dTag] = tag[1].split(":");
+        if (!isHex(author)) {
+          throw new Error(`Invalid author in A tag: ${tag[1]}`);
+        }
         return new NostrLink(NostrPrefix.Address, dTag, Number(kind), author, relays, "root");
       }
       case "a": {
         const [kind, author, dTag] = tag[1].split(":");
+        if (!isHex(author)) {
+          throw new Error(`Invalid author in a tag: ${tag[1]}`);
+        }
         return new NostrLink(NostrPrefix.Address, dTag, Number(kind), author, relays, tag[3]);
       }
     }
     throw new Error("Unknown tag!");
   }
 
+  static tryFromTag(tag: Array<string>, author?: string, kind?: number) {
+    try {
+      return NostrLink.fromTag(tag, author, kind);
+    } catch (e) {
+      // ignored
+    }
+  }
+
   static fromTags(tags: ReadonlyArray<Array<string>>) {
     return removeUndefined(
       tags.map(a => {