Redirection post.php after submitting editions

Hi. I have a project that was hacked and it added some weired code in some files. I removed the malicious code, but unintentionally I must remove important code, because now when I update a page / article whatever this page isn’t reloaded. My editions are submited but the page stops post.php file. What should I do for the page shows the previous page?? I don’t want to install the theme again because I spend so many hours customize it.

Thanks