Fatal error: Uncaught exception Error with message Call to undefined method PCT\ThemeInstaller\SystemCallbacks::injectScripts() thrown in system/modules/core/library/Contao/Template.php on line 273

#0 system/modules/core/classes/FrontendTemplate.php(46): Contao\Template->parse()
#1 system/modules/core/modules/Module.php(311): Contao\FrontendTemplate->parse()
#2 system/modules/core/library/Contao/Controller.php(321): Contao\Module->generate()
#3 system/modules/core/pages/PageRegular.php(133): Contao\Controller::getFrontendModule(Object(Contao\ModuleModel), 'header')
#4 system/modules/core/controllers/FrontendIndex.php(285): Contao\PageRegular->generate(Object(Contao\PageModel), true)
#5 index.php(20): Contao\FrontendIndex->run()
#6 {main}