I have set up a simple test form to receive payments ('Email Invoice' in Settings Payment Tab).
The following error occurs :-

'Your form could not be submitted for the following reason(s):

Warning: [ err 2/line 390/config.cls.php] session_start(): open(/var/lib/php/session/sess_o8h1rdju2l8atlm2rjrqvpt016, O_RDWR) failed: Permission denied (13)'

Using one of the Payments Templates also produces the same error.


Help please.

Sounds like PHP Sessions are not enabled. Contact your hosting provider and have them enable PHP Sessions and that should fix you up.