Just thought I'd post this here because I might need to find it later on (even though it appears that you don't allow Google to index these posts... tsk tsk tsk)

So, if you are experiencing an issue upon logging out of JomSocial and you are using jSecure on your site... you will probably get a flash of the following type of error
1
Warning: Cannot modify header information - headers already sent by (output started at /home/staging/public_html/xxx/plugins/system/jsecure/jsecure.php:43) in /home/staging/public_html/xxx/components/com_community/libraries/core.php on line 520

Warning: Cannot modify header information - headers already sent by (output started at /home/staging/public_html/xxx/plugins/system/jsecure/jsecure.php:43) in /home/staging/public_html/xxx/libraries/joomla/session/session.php on line 694

If so, I've found a simple solution.
You will need to edit the core file of jsecure (not considered a core hack because generally you'll never update this file).
Find this file > plugins/system/jsecure/jsecure.php
Edit the following block of code on or about line 40

function onUserLogout() {
	
	 self::$_configuration = 1;
	 echo self::$_configuration;
	 $session    =& JFactory::getSession();
	 $this->params->logout = true;
	}

function onUserLogout() {
	
	 self::$_configuration = 1;
	 //echo self::$_configuration;
	 $session    =& JFactory::getSession();
	 $this->params->logout = true;
	}

Hi, Norm Douglas.

Thank you for sharing your solution.
PHP warnings are just warnings not error. So they should not affect system performance.
You can hide them by setting Backend -> Global Configuration -> Server -> Error Reporting -> System Default (or None).

Thanks Michael... however you're not entirely correct.
Disabling error reporting is not a good idea... and in this instance, altering the reporting level either at the Joomla config and or via php.ini did nothing to change this.

Therefore the suggestion stands.

Whilst there was no "system performance" issues... the error was not ideal.