diff --git a/kernel/filesys/tree.go b/kernel/filesys/tree.go
index fd6e067f1..dd8d5ce19 100644
--- a/kernel/filesys/tree.go
+++ b/kernel/filesys/tree.go
@@ -270,7 +270,7 @@ func parseJSON2Tree(boxID, p string, jsonData []byte, luteEngine *lute.Lute) (re
 func ReadDocIAL(data []byte) (ret map[string]string) {
 	ret = map[string]string{}
 	val := jsoniter.Get(data, "Properties")
-	if nil == val {
+	if nil == val || val.ValueType() == jsoniter.InvalidValue {
 		return
 	}
 	val.ToVal(&ret)