blog not showing online due to theme not installing

i tried installing today the greek restaurant theme & when it installed, it won’t show my blog on my audrineisamom.com site. message me privately asap as to how to fix this asap bec. i need to change the lay-out of my blog. i tried logging in to my www.ads-software.com account but it’s showing this:

Warning: require_once(wp_bootstrap_navwalker.php): failed to open stream: No such file or directory in H:\root\home\isamom-001\www\site1\wp-content\themes\greek-restaurant\functions.php on line 130

Fatal error: require_once(): Failed opening required ‘wp_bootstrap_navwalker.php’ (include_path=’.;c:\php54\includes;c:\php54\pear’) in H:\root\home\isamom-001\www\site1\wp-content\themes\greek-restaurant\functions.php on line 130