phpGrid requies session to work.
First of all, if you have access to php.ini, check if path in session.save_path is valid and writable. In Linux, by default, the path is /var/php_sessions/.
In addition, please make sure session.auto_start must be set to "1" in php.ini.
Some web hosting services such as iPage, disallows shared user session folder for security reasons. Users MUST create and maintain their own session folder.
If you don’t want to deal with all those and prefer more loose security hosting, we recommend bluehost or stablehost.