2강 Board.xml에 만들 때 오류를 어떻게 해결해야 하나

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.demo.mvc.repository.BoardRepository">
	<select id="getList" parameterType="com.example.demo.mvc.domain.Board" resultType="com.example.demo.mvc.domain.Board">
		SELECT
		B.BOARD_SEQ,
		B.TITLE,
		B.CONTENTS,
		B.REG_DATE
		FROM T_BOARD B
		ORDER BY B.REG_DATE DESC
	</select>

	<select id="get" parameterType="com.example.demo.mvc.domain.Board" resultType="com.example.demo.mvc.domain.Board">
		SELECT
		B.BOARD_SEQ,
		B.TITLE,
		B.CONTENTS,
		B.REG_DATE
		FROM T_BOARD B
		WHERE B.BOARD_SEQ = #{boardSeq}
	</select>

	<insert id="save" parameterType="com.example.demo.mvc.domain.Board">
		INSERT INTO T_BOARD
		(
			TITLE,
			CONTENTS,
			REG_DATE
		)
		VALUES
		(
			#{title},
			#{contents},
			NOW()
		)
	</insert>

	<update id="update" parameterType="com.example.demo.mvc.domain.Board">
		UPDATE T_BOARD
		SET
			TITLE = #{title},
			CONTENTS = #{contents}
		WHERE BOARD_SEQ = #{boardSeq}
	</update>

	<delete id="delete" parameterType="com.example.demo.mvc.domain.Board">
		DELETE FROM T_BOARD
		WHERE BOARD_SEQ = #{boardSeq}
	</delete>
</mapper>

이 코드에서

http://mybatis.org/dtd/mybatis-3-mapper.dtd 이부분에서는 Downloading external resources is disabled. 라는 오류가 나오고요

<mapper> 부분에서는

Element type "mapper" must be declared. 라는 오류가 나오

<select> 부분도

Element type "select" must be declared. 라는 오류가 나옵니다

어떻게 해결해야 하지요?