我过去在自定义侧边栏方面也遇到过类似的问题。这是由于使用不当造成的<ul> 和<li> 标签。我正在侧边栏中添加它们。php文件，而不是函数内部。现在我使用这段代码，有了6个活动小部件，我就没有错误了。查看代码，如果您有任何问题，请告诉我：

functions.php

<?php
  // REGISTER THE SIDBARS
  if (!function_exists( \'ideatree_widgets_init\' )) {
   function ideatree_widgets_init() {
    register_sidebar(array(
      \'name\' => __( \'Primary Widget Area\', \'ideatree\' ), 
      \'id\' => \'primary-widget-area\', 
      \'description\' => \'The primary widget area\', \'ideatree\', 
      \'before_widget\' => \'<ul><li id="%1$s" class="widget-container %2$s">\', 
      \'after_widget\' => \'</li></ul>\', 
      \'before_title\' => \'<h3 class="widgettitle">\', 
      \'after_title\' => \'</h3>\',)
      );
    register_sidebar(array(
      \'name\' => \'Secondary Widget Area\', \'ideatree\', 
      \'id\' => \'secondary-widget-area\', 
      \'description\' => \'The secondary widget area\', \'ideatree\', 
      \'before_widget\' => \'<ul><li id="%1$s" class="widget-container %2$s">\', 
      \'after_widget\' => \'</li></ul>\', 
      \'before_title\' => \'<h3 class="widgettitle">\', 
      \'after_title\' => \'</h3>\',)
      );

      }
    add_action(\'widgets_init\', \'ideatree_widgets_init\');
    }
  ?>

sidebar.php

<div class="wrapper sidebar">
  <div id="upper-sidebar">
    <?php if ( ! dynamic_sidebar( \'primary-widget-area\' ) ) : ?>
    <?php endif; ?>
  </div><!-- END UPPER-SIDEBAR -->
  <div id="lower-sidebar">
    <?php if ( ! dynamic_sidebar( \'secondary-widget-area\' ) ) : ?>
    <?php endif; ?>
  </div><!-- END LOWER-SIDEBAR -->
</div><!-- END SIDEBAR -->