title: cvc-elt.1: Cannot find the declaration of element 'configuration'
body: <p>I want to use Logback in my Web Project,but in logback.xml there is a problem:</p>
  
  <blockquote>
    <p>cvc-elt.1: Cannot find the declaration of element 'configuration'.</p>
  </blockquote>
  
  <p>Here is my XML:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;configuration&gt;
  
      &lt;property name="USER_HOME" value="logs" /&gt;
      &lt;property scope="context" name="FILE_NAME" value="mylog-logback" /&gt;
  
      &lt;timestamp key="byDay" datePattern="yyyy-MM-dd" /&gt;
  
      &lt;appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender"&gt;
          &lt;encoder&gt;
              &lt;pattern&gt;%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
              &lt;/pattern&gt;
          &lt;/encoder&gt;
      &lt;/appender&gt;
  
      &lt;appender name="file"
          class="ch.qos.logback.core.rolling.RollingFileAppender"&gt;
          &lt;file&gt;${USER_HOME}/${FILE_NAME}.log&lt;/file&gt;
  
          &lt;rollingPolicy class="ch.qos.logback.core.rolling.FixedWindowRollingPolicy"&gt;
              &lt;fileNamePattern&gt;${USER_HOME}/${byDay}/${FILE_NAME}-${byDay}-%i.log.zip
              &lt;/fileNamePattern&gt;
              &lt;minIndex&gt;1&lt;/minIndex&gt;
              &lt;maxIndex&gt;10&lt;/maxIndex&gt;
          &lt;/rollingPolicy&gt;
  
          &lt;triggeringPolicy
              class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy"&gt;
              &lt;maxFileSize&gt;5MB&lt;/maxFileSize&gt;
          &lt;/triggeringPolicy&gt;
          &lt;encoder&gt;
              &lt;pattern&gt;%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
              &lt;/pattern&gt;
          &lt;/encoder&gt;
  
      &lt;/appender&gt;
  
      &lt;logger name="com.linkcos.object.*" level="track" additivity="false"&gt;
          &lt;appender-ref ref="file" /&gt;
          &lt;!-- &lt;appender-ref ref="STDOUT" /&gt; --&gt;
      &lt;/logger&gt;
  
      &lt;root level="info"&gt;
          &lt;appender-ref ref="file" /&gt;
          &lt;appender-ref ref="STDOUT" /&gt;
      &lt;/root&gt;
  &lt;/configuration&gt;
  </code></pre>
  
  <p>This is really a strange question,please help me!</p>