diff --git a/system3-nonconformance/web/static/js/core/auth-manager.js b/system3-nonconformance/web/static/js/core/auth-manager.js
index dbc93c5..aa72b69 100644
--- a/system3-nonconformance/web/static/js/core/auth-manager.js
+++ b/system3-nonconformance/web/static/js/core/auth-manager.js
@@ -65,11 +65,14 @@ class AuthManager {
      */
     _getUser() {
         const ssoUser = this._cookieGet('sso_user') || localStorage.getItem('sso_user');
-        if (ssoUser) {
+        if (ssoUser && ssoUser !== 'undefined' && ssoUser !== 'null') {
             try { return JSON.parse(ssoUser); } catch(e) {}
         }
         const userStr = localStorage.getItem('currentUser');
-        return userStr ? JSON.parse(userStr) : null;
+        if (userStr && userStr !== 'undefined' && userStr !== 'null') {
+            try { return JSON.parse(userStr); } catch(e) {}
+        }
+        return null;
     }
 
     /**
diff --git a/system3-nonconformance/web/sw.js b/system3-nonconformance/web/sw.js
index e51942a..09b77ae 100644
--- a/system3-nonconformance/web/sw.js
+++ b/system3-nonconformance/web/sw.js
@@ -3,9 +3,9 @@
  * M-Project 작업보고서 시스템
  */
 
-const CACHE_NAME = 'mproject-v1.0.1';
-const STATIC_CACHE = 'mproject-static-v1.0.1';
-const DYNAMIC_CACHE = 'mproject-dynamic-v1.0.1';
+const CACHE_NAME = 'mproject-v1.0.3';
+const STATIC_CACHE = 'mproject-static-v1.0.3';
+const DYNAMIC_CACHE = 'mproject-dynamic-v1.0.3';
 
 // 캐시할 정적 리소스
 const STATIC_ASSETS = [
@@ -112,15 +112,20 @@ self.addEventListener('activate', (event) => {
 self.addEventListener('fetch', (event) => {
     const { request } = event;
     const url = new URL(request.url);
-    
+
+    // POST 등 GET 이외 요청은 캐시 불가 → 기본 처리
+    if (request.method !== 'GET') {
+        return;
+    }
+
     // CORS 요청이나 외부 도메인은 기본 처리
     if (url.origin !== location.origin && !isCDNResource(url)) {
         return;
     }
-    
+
     // 캐시 전략 결정
     const strategy = getCacheStrategy(request.url);
-    
+
     event.respondWith(
         handleRequest(request, strategy)
     );
@@ -197,18 +202,19 @@ async function cacheFirst(request) {
  */
 async function staleWhileRevalidate(request) {
     const cachedResponse = await caches.match(request);
-    
+
     // 백그라운드에서 업데이트
     const networkResponsePromise = fetch(request)
-        .then((networkResponse) => {
+        .then(async (networkResponse) => {
             if (networkResponse.ok) {
-                const cache = caches.open(DYNAMIC_CACHE);
-                cache.then(c => c.put(request, networkResponse.clone()));
+                const responseToCache = networkResponse.clone();
+                const cache = await caches.open(DYNAMIC_CACHE);
+                cache.put(request, responseToCache);
             }
             return networkResponse;
         })
         .catch(() => null);
-    
+
     // 캐시된 응답이 있으면 즉시 반환, 없으면 네트워크 대기
     return cachedResponse || await networkResponsePromise;
 }