Contact form is not working

Hi Gavick support,

Needing help to fix an issue with contact form.... suddenly stops working, the issue is that after press the send button into contact page it shows an awful big error message, as follows:

Warning: session_start(): Failed to decode session object. Session has been destroyed in /home/chriscab/public_html/libraries/joomla/session/session.php on line 665

Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /home/chriscab/public_html/libraries/joomla/session/session.php:665) in /home/chriscab/public_html/libraries/joomla/session/session.php on line 665
Error displaying the error page: Application Instantiation Error: Error initialising the session.


My site is:
http://www.chriscaballero.photography/contacto

Please advise

It doesn't look like anything related to the template itself.
I have searched Google and I found this info:
http://forum.joomla.org/viewtopic.php?f=621&t=582860