PROBLEM IDENTIFIED!
The critical error was caused because I use CAPTCHA fields and for some reason our server no longer has access to the GD and FreeType libraries that are essential, to the CAPTCHA process.
Thank you Erik for your help but I am sorry to say that I have no access to root directories or the skills to alter files such as .php etc. Thanks anyway. I’ve taken out the CAPTCHA fields and all is well – hopefully I wont get lots of spam -= we’ll see!
Thanks anyway.