Fatal error: Uncaught Error: Call to a member function getBackButtonHtml() on null in /home/fastmicr/public_html/bg.livolo.bg/vendor/magento/module-newsletter/view/adminhtml/templates/queue/edit.phtml:11 Stack trace: #0 {main} thrown in /home/fastmicr/public_html/bg.livolo.bg/vendor/magento/module-newsletter/view/adminhtml/templates/queue/edit.phtml on line 11