diff --git a/troubleshooting/250826_happybell80_rb8001_이중저장구현.md b/troubleshooting/250826_happybell80_rb8001_이중저장구현.md
index 70052a6..1461d5e 100644
--- a/troubleshooting/250826_happybell80_rb8001_이중저장구현.md
+++ b/troubleshooting/250826_happybell80_rb8001_이중저장구현.md
@@ -151,6 +151,65 @@ graph LR
 
 ---
 
+## 추가 문제 해결 (user_id UUID 타입 불일치)
+
+### 발견된 문제
+1. **PostgreSQL 저장 실패**
+   ```
+   PostgreSQL save failed: invalid input syntax for type uuid: "system"
+   PostgreSQL save failed: invalid input syntax for type uuid: "U0925SXQFDK"
+   ```
+
+2. **원인 분석**
+   - conversation_logs 테이블의 user_id가 UUID 타입
+   - rb8001은 Slack user ID (문자열) 전송
+   - UUID 변환 불가능한 값으로 저장 실패
+
+### DB 스키마 수정 (51123 서버)
+```sql
+-- slack_user_id 컬럼 추가
+ALTER TABLE conversation_logs 
+ADD COLUMN slack_user_id VARCHAR(255);
+
+-- user_id를 nullable로 변경
+ALTER TABLE conversation_logs 
+ALTER COLUMN user_id DROP NOT NULL;
+```
+
+### rb8001 코드 수정 필요
+```python
+# router.py:338 수정
+conversation_log = ConversationLog(
+    robeing_id=settings.ROBEING_ID,
+    slack_user_id=user_id,  # user_id 대신 slack_user_id 사용
+    channel_id=channel,
+    message=message,
+    response=response,
+    intent=intent,
+    confidence=confidence
+)
+```
+
+### database.py 모델 수정
+```python
+class ConversationLog(Base):
+    """대화 로그 테이블"""
+    __tablename__ = "conversation_logs"
+    
+    id = Column(Integer, primary_key=True, index=True)
+    robeing_id = Column(String, index=True)
+    user_id = Column(String, nullable=True)  # UUID 타입, nullable
+    slack_user_id = Column(String)  # Slack ID 저장용
+    channel_id = Column(String)
+    message = Column(String)
+    response = Column(String)
+    intent = Column(String)
+    confidence = Column(Float)
+    timestamp = Column(DateTime, default=datetime.utcnow)
+```
+
+---
+
 ## 모니터링
 
 ### 로그 확인