Template file ezplatform-form-builder/src/bundle/Resources/views/themes/standard/form_builder/default_form_view.html.twig has hardcoded field names inside, which leads to 500 errors when there is a content type with form field without title or form field identifiers:

An exception has been thrown during the rendering of a template ("Argument '$fieldIdentifier' is invalid: 'title' field not present on content #60 'Name'").

Steps to reproduce:
1. Clean installation of eZ Platform 2.3
2. Create a new Content Type: "Custom Form" with fields:

3. Create content with "Custom Form" Content Type.
4. Create new Landing Page, add Embed block, point to a newly created "Custom Form" Content Object.