I migrated content from my D7 site to a D8 clean install following the handbook. I did not install any other module except from the one already present in the clean install.
If I enable layout builder the sites goes blank (front and admin), giving the following error:
The website encountered an unexpected error. Please try again later.
Error: Call to a member function getLabel() on null in Drupal\layout_builder\Plugin\Derivative\FieldBlockDeriver->getDerivativeDefinitions() (line 111 of core/modules/layout_builder/src/Plugin/Derivative/FieldBlockDeriver.php).I tried the same procedure also on a clean install of v 8.6.0-rc1, with the same results.
If I add a null check on $field_definition, the site recovers, but another error shows:
Notice: Undefined index: comment_body in Drupal\layout_builder\Plugin\Derivative\FieldBlockDeriver->getDerivativeDefinitions() (line 100 of core/modules/layout_builder/src/Plugin/Derivative/FieldBlockDeriver.php).