No grammar constraints (DTD or XML schema) detected for the document

No grammar constraints (DTD or XML schema) detected for the document.

Change out Context with whatever the root element name is.

参考：

1、https://www.rodneybeede.com/No_grammar_constraints__DTD_or_XML_schema__detected_for_the_document.html

2、http://stackoverflow.com/questions/4551783/no-grammar-constraints-dtd-or-xml-schema-detected-for-the-document