Frank Guilfoyle

Hello and can someone please help, Our website and a section in the dashboard are telling us that we have a Fatal error: Uncaught --> Smarty: unable to write file. this appears at the shopping cart section when you try to buy. It also appears in message and cart section on our dash board. So we are new to this world and really need help here, we are losing our first hard won customers. So can some please help. Kindest regards Frank - Ireland