Call to method sanitize() on an unknown class Symfony\Component\HtmlSanitizer\HtmlSanitizer.

Method Shopsys\FrameworkBundle\Component\GrapesJs\GrapesJsParser::getConfiguredSanitizer() has invalid return type Symfony\Component\HtmlSanitizer\HtmlSanitizer.

Method Shopsys\FrameworkBundle\Component\GrapesJs\GrapesJsParser::getConfiguredSanitizer() has invalid return type Symfony\Component\HtmlSanitizer\HtmlSanitizer.

Call to method allowSafeElements() on an unknown class Symfony\Component\HtmlSanitizer\HtmlSanitizerConfig.

Instantiated class Symfony\Component\HtmlSanitizer\HtmlSanitizerConfig not found.

Access to constant HEAD_ELEMENTS on an unknown class Symfony\Component\HtmlSanitizer\Reference\W3CReference.

Access to constant BODY_ELEMENTS on an unknown class Symfony\Component\HtmlSanitizer\Reference\W3CReference.

Instantiated class Symfony\Component\HtmlSanitizer\HtmlSanitizer not found.