Found issue, site branding block was removed. Re-added it to navbar section and it works fine.
Sorry about that.
I am not sure this is working for a fresh install.
I just did a fresh install of 10.0.0-rc2
I cannot add a heading to anything in layout builder, I get "Oops, something went wrong. Check your browser's developer console for more details."
This is what I see in console:
AjaxError:
An AJAX HTTP error occurred.
HTTP Result Code: 500
Debugging information follows.
Path: /layout_builder/add/block/overrides/node.4/0/section_header/inline_block%3Avarbase_heading_block
StatusText: 500 Service unavailable (with message)
ResponseText: The website encountered an unexpected error. Try again later.Error: Call to a member function bundle() on null in _block_form_alter_block_type_form_alter_inline_block_process() (line 81 of modules/contrib/block_form_alter/block_form_alter.module). call_user_func_array('_block_form_alter_block_type_form_alter_inline_block_process', Array) (Line: 1013)
Drupal\Core\Form\FormBuilder->doBuildForm('layout_builder_add_block', Array, Object) (Line: 1076)
Drupal\Core\Form\FormBuilder->doBuildForm('layout_builder_add_block', Array, Object) (Line: 1076)
Drupal\Core\Form\FormBuilder->doBuildForm('layout_builder_add_block', Array, Object) (Line: 579)
I am happy to help debug this.