diff --git a/src/main/java/com/eactive/eai/common/authoutbound/AccessTokenManagerByDB.java b/src/main/java/com/eactive/eai/common/authoutbound/AccessTokenManagerByDB.java
index e602393..af6a344 100644
--- a/src/main/java/com/eactive/eai/common/authoutbound/AccessTokenManagerByDB.java
+++ b/src/main/java/com/eactive/eai/common/authoutbound/AccessTokenManagerByDB.java
@@ -316,9 +316,17 @@ public class AccessTokenManagerByDB implements Lifecycle {
 				if(service != null) {
 					logger.debug("Executing token service of type: {} for adapter group: {}", type, adapterGroupName);
 					accessToken = (AccessTokenVO) service.execute(adapterGroupName, properties, outboundOAuthCredentialVo);
+
+					// 발급에 실패했는데도 빈 토큰을 반환하는 구현체가 있다. 그대로 캐시되면
+					// 만료시각이 없어 재발급 대상이 되지 않으므로 실패로 처리한다.
+					if (accessToken == null || StringUtils.isBlank(accessToken.getAccessToken())) {
+						logger.error("Issued token is empty. type: {}, adapter group: {}", type, adapterGroupName);
+						return null;
+					}
+
 					logger.info("New token issued successfully for adapter group: {}", adapterGroupName);
 					return accessToken;
-					
+
 				} else {
 					logger.warn("Token service not found for type: {} and adapter group: {}", type, adapterGroupName);
 				}
diff --git a/src/main/java/com/eactive/eai/common/session/SessionManagerForIgnite.java b/src/main/java/com/eactive/eai/common/session/SessionManagerForIgnite.java
index 2411524..352f34c 100644
--- a/src/main/java/com/eactive/eai/common/session/SessionManagerForIgnite.java
+++ b/src/main/java/com/eactive/eai/common/session/SessionManagerForIgnite.java
@@ -938,7 +938,13 @@ public class SessionManagerForIgnite extends SessionManager {
 
 			    logger.debug(String.format("getting token is null or expired borrow new token =%s", token));
 
-			    cacheOutBoundAccessToken.put(key, token);
+			    // 빈 토큰은 캐시하지 않는다. 발급 구현체가 실패를 삼키고 빈 토큰을 반환하는 경우가 있는데,
+			    // 그게 캐시되면 만료시각이 없어 isExpired() 가 계속 false 라 재발급되지 않는다.
+			    if (token != null && token.getAccessToken() != null && token.getAccessToken().trim().length() > 0) {
+				cacheOutBoundAccessToken.put(key, token);
+			    } else {
+				logger.warn("Empty access token is not cached. key=" + key);
+			    }
 			}
 	            }
 	            else