Fatal error: Uncaught Error: Class "Drupal\Core\Block\BlockBase" not found in /home/fnbrshareacopy/public_html/modules/contrib/formblock/src/Plugin/Block/UserRegisterBlock.php:29 Stack trace: #0 {main} thrown in /home/fnbrshareacopy/public_html/modules/contrib/formblock/src/Plugin/Block/UserRegisterBlock.php on line 29