Fatal Error

My webhost broke my site and now when I try to activate this plugin I get a fatal error message. It was working fine up until the time they messed with it. How do I fix this?
Warning: require_once(/hermes/bosoraweb149/b1644/sl.patchesa/public_html/wordpress1/wp-content/plugins/insert-headers-and-footers/_modules/dashboard/dashboard.php): failed to open stream: No such file or directory in /hermes/bosoraweb149/b1644/sl.patchesa/public_html/wordpress1/wp-content/plugins/_old/ihaf.php on line 46 Fatal error: require_once(): Failed opening required ‘/hermes/bosoraweb149/b1644/sl.patchesa/public_html/wordpress1/wp-content/plugins/insert-headers-and-footers/_modules/dashboard/dashboard.php’ (include_path=’.:/usr/local/lib/php-5.5.6-amd64/lib/php’) in /hermes/bosoraweb149/b1644/sl.patchesa/public_html/wordpress1/wp-content/plugins/_old/ihaf.php on line 46 Warning: Unknown: open(/var/php_sessions/sess_bd850eb24af2c2c0f38bb10968acaa16, O_RDWR) failed: No such file or directory (2) in Unknown on line 0 Warning: Unknown: Failed to write session data (files). Please verify that the current setting of session.save_path is correct (/var/php_sessions) in Unknown on line 0

https://wordpress.org/plugins/insert-headers-and-footers/