.打开Android studio什么都没做，建立一个新项目使用validate后出现这样的报错，请问这是什么问题

Question

Error:(1, 56) schema_reference.4: Failed to read schema document 'null', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>.Error:(1, 56) s4s-elt-invalid: Element 'x' is not a valid element in a schema document.Error:(1, 56) s4s-elt-schema-ns: The namespace of element 'x' must be from the schema namespace, 'http://www.w3.org/2001/XMLSchema'. Error:(7, 68) cvc-elt.1.a: Cannot find the declaration of element 'android.support.constraint.ConstraintLayout'.