diff --git a/src/core/common/utility.go b/src/core/common/utility.go
index c8ea35c99..516fa6bbe 100644
--- a/src/core/common/utility.go
+++ b/src/core/common/utility.go
@@ -466,7 +466,7 @@ func GetConnConfigList() (ConnConfigList, error) {
 		if err != nil {
 			CBLog.Error(err)
 			content := ConnConfigList{}
-			err := fmt.Errorf("an error occurred while requesting to CB-Spider")
+			err := fmt.Errorf("Error from CB-Spider: " + err.Error())
 			return content, err
 		}
 
diff --git a/src/core/mcir/securitygroup.go b/src/core/mcir/securitygroup.go
index 8d60037a0..c27158633 100644
--- a/src/core/mcir/securitygroup.go
+++ b/src/core/mcir/securitygroup.go
@@ -193,27 +193,35 @@ func CreateSecurityGroup(nsId string, u *TbSecurityGroupReq, option string) (TbS
 
 		if err != nil {
 			common.CBLog.Error(err)
-			err := fmt.Errorf("Cannot ListResourceId securityGroup")
+			err := fmt.Errorf("Cannot list vNet Ids for securityGroup")
 			return TbSecurityGroupInfo{}, err
 		}
 
-		var content struct {
-			VNet []TbVNetInfo `json:"vNet"`
-		}
-		content.VNet = resourceList.([]TbVNetInfo) // type assertion (interface{} -> array)
+		if resourceList != nil {
+			var content struct {
+				VNet []TbVNetInfo `json:"vNet"`
+			}
+			content.VNet = resourceList.([]TbVNetInfo) // type assertion (interface{} -> array)
+
+			if len(resourceList.([]TbVNetInfo)) == 0 {
+				errString := "There is no " + common.StrVNet + " resource in " + nsId
+				err := fmt.Errorf(errString)
+				common.CBLog.Error(err)
+				return TbSecurityGroupInfo{}, err
+			}
 
-		if len(content.VNet) == 0 {
-			errString := "There is no " + common.StrVNet + " resource in " + nsId
+			// Assign random temporal ID to u.VNetId (should be in the same Connection with SG)
+			for _, r := range content.VNet {
+				if r.ConnectionName == u.ConnectionName {
+					u.VNetId = r.Id
+				}
+			}
+		} else {
+			errString := "nil was returned for vNet list in " + nsId
 			err := fmt.Errorf(errString)
 			common.CBLog.Error(err)
 			return TbSecurityGroupInfo{}, err
 		}
-
-		for _, r := range content.VNet {
-			if r.ConnectionName == u.ConnectionName {
-				u.VNetId = r.Id
-			}
-		}
 	}
 
 	vNetInfo := TbVNetInfo{}