I am glad to see the cause of your problem has been found. Sometimes threads get missed and while it sometimes takes a few days to pick up on threads, any longer usually means it has been missed which appears to be the case with you here. Hopefully you are able to rectify your server limitations to rectify this fault.
For others. Ron4mac investigated and discovered the server settings were limiting the amount of memory available to PHP scripts. This is a common problem many encounter not just with CPG, but with any PHP package such as Joomla, Wordpress etc. Hosts often, particularly shared hosting, set limits quite low. As server power has increased as well as the amount we now use them some hosts have not reviewed these low limits leading to more seeing issues like this. Some hosts allow you to change PHP limits, others do not. Sometimes this is done in the hosts control panel, sometimes via a PHP.ini file any sometimes in the .htaccess file. Only the host can advise where as all setups can be different. With blank page or error 500 problems such as this, it is always best to check your server logs or enable error reporting as a first resort into diagnosis as that is where the details of the error will be. Doing that will often save time, especially as we, or any other support forum for PHP scripts, will need that information to assist. Some hosts are very good at providing, or helping to provide this information. Other hosts make it a real chore. Whenever you setup with a new host it is always worth finding out all the details as to how to adjust PHP settings, error reporting and logs locations as this is really helpful when errors occur.