If it was the theme itself that was edited then all the code will be replaced by the new version (this goes for anything WordPress, including plugins so when you get custom coding don’t update). There is no way of getting custom code back unless there is a backup somewhere. Contact the developer who changed it to see if he/she has a backup.
So I fixed it. You have to download the file class-tgm-plugin-activation.php from this site: http://tgmpluginactivation.com/download/
Then FTP into your site and place it in the folder name zerif-lite. Refresh the site and it should work.
I am having the same issue as well. Anybody have a solution?
