Opencart açılmayan sayfa hatası

Arkadaşlar opencart 2.3.0.2 versiyonlu lisanslı tema ile sayfa kurdum. Ancak sayfamda google searchta tarama hataları kısmında açılmayan 6 sayfa var ve bunların çözümünü bulamadım. 2 hatayı aşağıya yazıyorum, rica etsem bilenler yardımcı olabilir mi acaba.

1 ) Warning: Cannot modify header information - headers already sent by (output started at /home/u7761996/public_html/catalog/language/tr-tr/common/footer.php:1) in /home/u7761996/public_html/catalog/view/theme/BurnEngine/template/error/not_found.tpl on line 1Warning: Cannot modify header information - headers already sent by (output started at /home/u7761996/public_html/catalog/language/tr-tr/common/footer.php:1) in /home/u7761996/public_html/catalog/view/theme/BurnEngine/template/error/not_found.tpl on line 1

2) Warning: Cannot modify header information - headers already sent by (output started at /home/u7761996/public_html/catalog/language/tr-tr/common/footer.php:1) in /home/u7761996/public_html/catalog/view/theme/BurnEngine/template/error/not_found.tpl on line 1Warning: Cannot modify header information - headers already sent by (output started at /home/u7761996/public_html/catalog/language/tr-tr/common/footer.php:1) in /home/u7761996/public_html/catalog/view/theme/BurnEngine/template/error/not_found.tpl on line 1

Bunları denediniz mi? Ben de bu hatayı aldığımda ob start çözmüştü
https://www.google.com/amp/s/www.erbilen.net/cannot-modify-header-information-headers-already-sent-by-hatasi-ve-cozumu/amp/