diff --git a/backend-spring/src/main/java/com/erp/config/GlobalExceptionHandler.java b/backend-spring/src/main/java/com/erp/config/GlobalExceptionHandler.java
index 0650f57a..1085973e 100644
--- a/backend-spring/src/main/java/com/erp/config/GlobalExceptionHandler.java
+++ b/backend-spring/src/main/java/com/erp/config/GlobalExceptionHandler.java
@@ -33,13 +33,7 @@ public class GlobalExceptionHandler {
     public ResponseEntity<ApiResponse<Void>> handleException(Exception e,
                                                               HttpServletRequest request) {
         log.error("Unhandled exception", e);
-        // QA 진단 임시 — root cause class + message 노출 (안정화 후 원복 예정)
-        String detail = e.getClass().getSimpleName() + ": " + (e.getMessage() != null ? e.getMessage() : "no message");
-        Throwable cause = e.getCause();
-        if (cause != null) {
-            detail += " | caused by " + cause.getClass().getSimpleName() + ": " + cause.getMessage();
-        }
         return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
-                .body(ApiResponse.error("[DEBUG] " + detail, request.getRequestURI()));
+                .body(ApiResponse.error("서버 내부 오류가 발생했습니다.", request.getRequestURI()));
     }
 }
diff --git a/backend-spring/src/main/java/com/erp/config/JacksonConfig.java b/backend-spring/src/main/java/com/erp/config/JacksonConfig.java
index ff6f11b4..c58c33a7 100644
--- a/backend-spring/src/main/java/com/erp/config/JacksonConfig.java
+++ b/backend-spring/src/main/java/com/erp/config/JacksonConfig.java
@@ -1,8 +1,9 @@
 package com.erp.config;
 
 import com.fasterxml.jackson.annotation.JsonInclude;
-import com.fasterxml.jackson.core.JsonGenerator;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
+import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 
@@ -13,6 +14,11 @@ public class JacksonConfig {
     public ObjectMapper objectMapper() {
         ObjectMapper mapper = new ObjectMapper();
         mapper.setSerializationInclusion(JsonInclude.Include.ALWAYS);
+        // Java 8 date/time (OffsetDateTime, LocalDateTime 등) 직렬화 지원.
+        // 커스텀 ObjectMapper 빈이 있으면 Spring Boot 자동 구성 모듈 등록이 적용되지
+        // 않으므로 명시적으로 등록한다.
+        mapper.registerModule(new JavaTimeModule());
+        mapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
         return mapper;
     }
 }