diff --git a/chatgpt-suno-tampermonkey.user.js b/chatgpt-suno-tampermonkey.user.js
index 3655511..c51028d 100644
--- a/chatgpt-suno-tampermonkey.user.js
+++ b/chatgpt-suno-tampermonkey.user.js
@@ -30,7 +30,7 @@
 (function () {
   "use strict";
 
-  const SCRIPT_VERSION = "0.9.5";
+  const SCRIPT_VERSION = "0.9.6";
   const STORAGE_KEY = "chatgptSunoPromptSlots";
   const SLOT_COUNT = 2;
   const isChatGPT = location.hostname.includes("chatgpt.com") || location.hostname.includes("chat.openai.com");
@@ -1024,6 +1024,15 @@
     return data;
   }
 
+  function hasHttpStatus(error, statuses) {
+    const message = String(error?.message || error || "");
+    return statuses.some((status) => message.startsWith(`${status} `) || message.includes(` ${status} `));
+  }
+
+  function shouldUseTampermonkeyFirst(url) {
+    return /^https?:\/\/cdn[0-9]*\.suno\.ai\//i.test(url);
+  }
+
   async function callSunoText(url, options = {}) {
     const page = typeof unsafeWindow !== "undefined" ? unsafeWindow : window;
     const headers = {
@@ -1031,7 +1040,7 @@
       ...(options.method && options.method !== "GET" && options.method !== "HEAD" ? { "content-type": "application/json" } : {}),
       ...(options.headers || {}),
     };
-    if (typeof GM_xmlhttpRequest === "function" && /^https?:\/\/[^/]*suno\./i.test(url)) {
+    if (typeof GM_xmlhttpRequest === "function" && shouldUseTampermonkeyFirst(url)) {
       return callTampermonkeyRequest(url, { ...options, headers });
     }
     try {
@@ -1207,6 +1216,7 @@
     try {
       await callSunoJson(`${base}/convert_wav/`, { method: "POST" });
     } catch (error) {
+      if (hasHttpStatus(error, [401, 403])) throw new Error("SUNO WAV 변환 권한이 없어. SUNO 페이지를 새로고침한 뒤 다시 시도해줘.");
       console.warn("[ChatGPT to Suno] convert_wav failed", error);
     }
 
@@ -1217,6 +1227,7 @@
         if (direct) return direct;
         if (await canReadUrl(cdnWavUrl)) return cdnWavUrl;
       } catch (error) {
+        if (hasHttpStatus(error, [401, 403])) throw new Error("SUNO WAV URL 권한이 없어. SUNO 페이지를 새로고침한 뒤 다시 시도해줘.");
         console.warn("[ChatGPT to Suno] wav_file failed", error);
         if (await canReadUrl(cdnWavUrl)) return cdnWavUrl;
       }
@@ -1229,11 +1240,11 @@
   async function prepareSunoWavCandidate(track) {
     if (!track.id) return extractWavUrl(track.wavUrl);
     const base = `https://studio-api-prod.suno.com/api/gen/${encodeURIComponent(track.id)}`;
-    const billingDownloadUrl = `https://studio-api-prod.suno.com/api/billing/clips/${encodeURIComponent(track.id)}/download/`;
     const cdnWavUrl = `https://cdn1.suno.ai/${encodeURIComponent(track.id)}.wav`;
     try {
       await callSunoJson(`${base}/convert_wav/`, { method: "POST" });
     } catch (error) {
+      if (hasHttpStatus(error, [401, 403])) throw new Error("SUNO WAV 변환 권한이 없어. SUNO 페이지를 새로고침한 뒤 다시 시도해줘.");
       console.warn("[ChatGPT to Suno] convert_wav failed; local retry will continue", error);
     }
     try {
@@ -1241,15 +1252,9 @@
       const direct = extractWavUrl(data);
       if (direct) return direct;
     } catch (error) {
+      if (hasHttpStatus(error, [401, 403])) throw new Error("SUNO WAV URL 권한이 없어. SUNO 페이지를 새로고침한 뒤 다시 시도해줘.");
       console.warn("[ChatGPT to Suno] wav_file probe failed; local retry will continue", error);
     }
-    try {
-      const data = await callSunoJson(billingDownloadUrl, { method: "GET" });
-      const direct = extractWavUrl(data);
-      if (direct) return direct;
-    } catch (error) {
-      console.warn("[ChatGPT to Suno] billing download probe failed; local retry will continue", error);
-    }
     return extractWavUrl(track.wavUrl) || cdnWavUrl;
   }
 
@@ -1262,18 +1267,20 @@
     try {
       await callSunoJson(`${base}/convert_wav/`, { method: "POST" });
     } catch (error) {
+      if (hasHttpStatus(error, [401, 403])) throw new Error("SUNO WAV 변환 권한이 없어. SUNO 페이지를 새로고침한 뒤 다시 시도해줘.");
       console.warn("[ChatGPT to Suno] convert_wav failed before browser download", error);
     }
 
     for (let attempt = 0; attempt < 20; attempt += 1) {
       try {
+        setStatus(statusTarget, `SUNO WAV URL 확인 중 ${attempt + 1}/20: ${track.title || track.id}`);
         const data = await callSunoJson(`${base}/wav_file/`, { method: "GET" });
         const direct = extractWavUrl(data);
         if (direct) candidates.push(direct);
       } catch (error) {
+        if (hasHttpStatus(error, [401, 403])) throw new Error("SUNO WAV URL 권한이 없어. SUNO 페이지를 새로고침한 뒤 다시 시도해줘.");
         console.warn("[ChatGPT to Suno] wav_file probe failed before browser download", error);
       }
-      candidates.push(`https://studio-api-prod.suno.com/api/billing/clips/${encodeURIComponent(track.id)}/download/`);
       candidates.push(`https://cdn1.suno.ai/${encodeURIComponent(track.id)}.wav`);
 
       for (const url of unique(candidates)) {