why does my shoutbox show this......

[Jason Black]

500 - Internal Server Error
The server encountered a problem while trying to fulfill your request. Please try again later.
If the error persists, please contact the website webmaster.
If you are the webmaster of this site please log in to Cpanel and check the Error Logs. You will find the exact reason for this error there.

Common reasons for this error are:

Incorrect file/directory permissions: 766 or 777.
The webserver does not process php/cgi scripts with higher permissions than 755. Change the permissions of your file/directory to 755 in order to solve this issue.

Incorrect Apache directives inside .htaccess file.
In case custom Apache directives have been added to the .htaccess file, the Internal Server Error means these directives are either not supported and should be removed or are incorrect and should be re-written.

Php directives set in the .htaccess file instead of the php.ini files.
All custom php settings (e.g. php_flag) must be placed inside a php.ini file. For each separate directory you should create its own php.ini file.

How do i fix this error?