plan2net/sierrha (packagist): 404 'not found' and 403 'forbidden' error handlers. The 404 handler shows custom content for missing pages but not resources like CSS or JS. The 403 handler redirects to a login URL on unauthorized access.
Keywords: error handler|extension|typo3|error page|site configuration|http status 403|http status 404|http error forbidden|http error not found|error-handler|error-handlers|site