FATAL ERROR

I have a bit of a problem this end – my web site went down yesterday and when you go to the site online this message comes up:

Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 122880 bytes) in /web/sites/_m/_j/_w/mjwarchitects.com/public/www/wp-content/plugins/gpress/gpress-admin/tpp_options-class.php on line 1147

Any thoughts what it could be and how to fix it?

Help appreciated.