报错：- cvc-complex-type.2.4.c: The matching wildcard is strict, but no declaration can be found for element 'dubbo:application'.

报错：- cvc-complex-type.2.4.c: The matching wildcard is strict, but no declaration can be found for element 'dubbo:application'.

	- cvc-complex-type.2.4.c: The matching wildcard is strict, but no declaration can be found for element 'dubbo:application'.
	- schema_reference.4: Failed to read schema document 'http://code.alibabatech.com/schema/dubbo/dubbo.xsd', 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>.

翻译：
——cvc-complex-type.2.4。c:匹配的通配符是严格的，但是元素“dubbo:application”没有声明。
——schema_reference。4:无法读取模式文档‘http://code.alibabatech.com/schema/dubbo/dubbo.xsd’，因为1)无法读取
找到文档;2)文件无法读取;3)文档的根元素不是。
原因：因为阿里http://code.alibabatech.com/schema/dubbo域名关闭，所以不能在线访问到http://code.alibabatech.com/schema/dubbo/dubbo.xsd文件。
解决：使用本地资源。
1、下载dubbo.xsd
下载地址 https://github.com/apache/incubator-dubbo/blob/master/dubbo-config/dubbo-config-spring/src/main/resources/META-INF/dubbo.xsd
2、偏好设置 - XML - XML Catalog - Add - Catelog Entry - File System...(选择上一步下载的文件位置) - key(添加后缀/dubbo.xsd) - ok
示例

Location /Users/acui/apache-maven-3.5.4/dubbo.xsd
Key http://dubbo.apache.org/schema/dubbo/dubbo.xsd

3、Validate或Update项目

参考：
The matching wildcard is strict, but no declaration can be found for element 'dubbo:application'
配置Dubbo Demo遇到的坑之一---找不到dubbo.xsd文件
no declaration can be found for element 'dubbo:application'