cant get a thumbnail contribution. to work

[Hound101]

Hi people,

 

I need help big time!! I cant get any thumbnail contributions to work at all, I have restored the original html code in html_output.php but now receive the following message: "Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /home/puregame/public_html/catalog/includes/functions/html_output.php:315) in /home/puregame/public_html/catalog/includes/functions/sessions.php on line 67" at the top of my websites pages (WWW.PUREGAMERZ.CO.UK).

 

Can anyone shed light on clearing this error message and also post some real basic simple steps for installing a thumbnail contribution that will work.

 

Thanks.