diff --git a/js/examples/nextjs/app/ui.tsx b/js/examples/nextjs/app/ui.tsx
index a8ca40a..f9a5339 100644
--- a/js/examples/nextjs/app/ui.tsx
+++ b/js/examples/nextjs/app/ui.tsx
@@ -142,7 +142,7 @@ export function DemoClient(): ReactElement {
   const [useStagingConnectBaseUrl, setUseStagingConnectBaseUrl] =
     useState(false);
   const [isConnectUrlTooltipOpen, setIsConnectUrlTooltipOpen] = useState(false);
-  const [worldIdVersion, setWorldIdVersion] = useState<"3.0" | "4.0">("3.0");
+  const [worldIdVersion, setWorldIdVersion] = useState<"3.0" | "4.0">("4.0");
   const [v4CredentialType, setV4CredentialType] =
     useState<V4CredentialType>("proof_of_human");
   const [presetKind, setPresetKind] = useState<PresetKind>("orb");
diff --git a/rust/core/src/bridge.rs b/rust/core/src/bridge.rs
index 8b7122a..910471b 100644
--- a/rust/core/src/bridge.rs
+++ b/rust/core/src/bridge.rs
@@ -636,7 +636,13 @@ impl BridgeConnection {
                 #[cfg(not(feature = "native-crypto"))]
                 let plaintext = decrypt(&self.key_bytes, &iv, &ciphertext)?;
 
-                let bridge_response: BridgeResponse = serde_json::from_slice(&plaintext)?;
+                let bridge_response: BridgeResponse =
+                    serde_json::from_slice(&plaintext).map_err(|_| {
+                        let raw = String::from_utf8_lossy(&plaintext);
+                        Error::BridgeError(format!(
+                            "World App returned an unrecognized response. This may indicate a version mismatch. Raw response: {raw}"
+                        ))
+                    })?;
 
                 match bridge_response {
                     BridgeResponse::Error { error_code } => Ok(Status::Failed(error_code)),