Fatal error: Uncaught exception InvalidArgumentException with message Invalid output format xhtml thrown in system/modules/core/library/Contao/Controller.php on line 54
#0 system/modules/core/library/Contao/BaseTemplate.php(81): Contao\Controller::getTemplate('mod_html', 'xhtml')
#1 system/modules/core/library/Contao/Template.php(238): Contao\BaseTemplate->parse()
#2 system/modules/core/classes/FrontendTemplate.php(38): Contao\Template->parse()
#3 system/modules/core/modules/Module.php(178): Contao\FrontendTemplate->parse()
#4 system/modules/core/library/Contao/Controller.php(310): Contao\Module->generate()
#5 system/modules/core/pages/PageRegular.php(129): Contao\Controller::getFrontendModule(Object(Contao\ModuleModel), 'left')
#6 system/modules/core/controllers/FrontendIndex.php(250): Contao\PageRegular->generate(Object(Contao\PageModel), true)
#7 index.php(20): Contao\FrontendIndex->run()
#8 {main}