When plugin enabled and user logs in, a blank white page is displayed.Debug.log says:

2014-05-12 22:01:58 Debug: Notice (8): Undefined variable: jsnsocial_setting in [C:\apache\htdocs\plugins\jsn\socialnetwork\app\View\Layouts\default.ctp, line 84]
Trace:
include - APP\View\Layouts\default.ctp, line 84
View::_evaluate() - CORE\Cake\View\View.php, line 956
View::_render() - CORE\Cake\View\View.php, line 918
View::renderLayout() - CORE\Cake\View\View.php, line 546
View::render() - CORE\Cake\View\View.php, line 490
Controller::render() - CORE\Cake\Controller\Controller.php, line 963
ExceptionRenderer::_outputMessage() - CORE\Cake\Error\ExceptionRenderer.php, line 287
ExceptionRenderer::error500() - CORE\Cake\Error\ExceptionRenderer.php, line 256
ExceptionRenderer::render() - CORE\Cake\Error\ExceptionRenderer.php, line 189
ErrorHandler::handleException() - CORE\Cake\Error\ErrorHandler.php, line 134
[main] - [internal], line ??

Error.log has:

2014-05-12 22:01:58 Warning: Warning (2): Invalid argument supplied for foreach() in [C:\apache\htdocs\plugins\jsn\socialnetwork\app\View\Elements\main_menu.ctp, line 34]
Trace:
include - APP\View\Elements\main_menu.ctp, line 34
View::_evaluate() - CORE\Cake\View\View.php, line 956
View::_render() - CORE\Cake\View\View.php, line 918
View::_renderElement() - CORE\Cake\View\View.php, line 1219
View::element() - CORE\Cake\View\View.php, line 425
include - APP\View\Layouts\default.ctp, line 32
View::_evaluate() - CORE\Cake\View\View.php, line 956
View::_render() - CORE\Cake\View\View.php, line 918
View::renderLayout() - CORE\Cake\View\View.php, line 546
View::render() - CORE\Cake\View\View.php, line 490
Controller::render() - CORE\Cake\Controller\Controller.php, line 963
ExceptionRenderer::_outputMessage() - CORE\Cake\Error\ExceptionRenderer.php, line 287
ExceptionRenderer::error500() - CORE\Cake\Error\ExceptionRenderer.php, line 256
ExceptionRenderer::render() - CORE\Cake\Error\ExceptionRenderer.php, line 189
ErrorHandler::handleException() - CORE\Cake\Error\ErrorHandler.php, line 134
[main] - [internal], line ??

Saw mention of deleting /plugins/jsn/socialnetwork/app/tmp/cache directory but no effect.

At the moment this is on localhost whilst I play.