reverted:
--- b/core/modules/help/help.api.php
+++ a/core/modules/help/help.api.php
@@ -46,8 +46,7 @@
   switch ($route_name) {
     // Main module help for the block module.
     case 'help.page.block':
+      return '<p>' . t('Blocks are boxes of content rendered into an area, or region, of a web page. The default theme Bartik, for example, implements the regions "Sidebar first", "Sidebar second", "Featured", "Content", "Header", "Footer", etc., and a block may appear in any one of these areas. The <a href="!blocks">blocks administration page</a> provides a drag-and-drop interface for assigning a block to a region, and for controlling the order of blocks within regions.', array('!blocks' => \Drupal::url('block.admin_display'))) . '</p>';
-      $block_page = \Drupal::moduleHandler()->moduleExists('block') ? \Drupal::url('block.admin_display') : '#';
-      return '<p>' . t('Blocks are boxes of content rendered into an area, or region, of a web page. The default theme Bartik, for example, implements the regions "Sidebar first", "Sidebar second", "Featured", "Content", "Header", "Footer", etc., and a block may appear in any one of these areas. The <a href="!blocks">blocks administration page</a> provides a drag-and-drop interface for assigning a block to a region, and for controlling the order of blocks within regions.', array('!blocks' => $block_page)) . '</p>';
 
     // Help for another path in the block module.
     case 'block.admin_display':