It was something like this Fatal error: Cannot redeclare get_comments_popup_template()(previously declared in /home/……./public_html/wp-includes/template.php:…) in /home/…../public_html/wp-includes/deprecated.php on line …..
but i solved it
I followed your manual update guide to remove .maintenance file and wp includes folder using FTP and upload wp includes folder of 4.5 version
It worked my site loads fine now
Anyways thanks for support
