error on RssRenderer.php on line 58 (no replies)

I'm using wordpress piwik plugin for this -
authenticspirituality.co.il
I have other websites on my piwik server that works correctly, but this one is stubborn!

Please help me,
the wordpress panel gives me the following error:
An error occured: Unknown site/blog. [Support]

but than -
Debugging -

Either allow_url_fopen has to be enabled or cURL has to be available:
cURL is available.
allow_url_fopen is enabled.


Inside piwik panel there is this error:

There is an error. Please report the message (Piwik 2.1.0) and full backtrace in the Piwik forums (please do a Search first as it might have been reported already!).

Notice: Trying to get property of non-object in /home/duranseo/piwik/plugins/ExampleRssWidget/RssRenderer.php on line 58

Backtrace -->

#0 Piwik\Error::errorHandler(...) called at [/home/duranseo/piwik/plugins/ExampleRssWidget/RssRenderer.php:58]
#1 Piwik\Plugins\ExampleRssWidget\RssRenderer->get(...) called at [/home/duranseo/piwik/plugins/ExampleRssWidget/Controller.php:25]
#2 Piwik\Plugins\ExampleRssWidget\Controller->rssPiwik(...) called at [:]
#3 call_user_func_array(...) called at [/home/duranseo/piwik/core/FrontController.php:521]
#4 Piwik\FrontController->doDispatch(...) called at [/home/duranseo/piwik/core/FrontController.php:84]
#5 Piwik\FrontController->dispatch(...) called at [/home/duranseo/piwik/core/dispatch.php:30]
#6 require_once(...) called at [/home/duranseo/piwik/index.php:47]


There is an error. Please report the message (Piwik 2.1.0) and full backtrace in the Piwik forums (please do a Search first as it might have been reported already!).

Notice: Trying to get property of non-object in /home/duranseo/piwik/plugins/ExampleRssWidget/RssRenderer.php on line 58

Backtrace -->

#0 Piwik\Error::errorHandler(...) called at [/home/duranseo/piwik/plugins/ExampleRssWidget/RssRenderer.php:58]
#1 Piwik\Plugins\ExampleRssWidget\RssRenderer->get(...) called at [/home/duranseo/piwik/plugins/ExampleRssWidget/Controller.php:25]
#2 Piwik\Plugins\ExampleRssWidget\Controller->rssPiwik(...) called at [:]
#3 call_user_func_array(...) called at [/home/duranseo/piwik/core/FrontController.php:521]
#4 Piwik\FrontController->doDispatch(...) called at [/home/duranseo/piwik/core/FrontController.php:84]
#5 Piwik\FrontController->dispatch(...) called at [/home/duranseo/piwik/core/dispatch.php:30]
#6 require_once(...) called at [/home/duranseo/piwik/index.php:47]


There is an error. Please report the message (Piwik 2.1.0) and full backtrace in the Piwik forums (please do a Search first as it might have been reported already!).

Warning: Invalid argument supplied for foreach() in /home/duranseo/piwik/plugins/ExampleRssWidget/RssRenderer.php on line 60

Backtrace -->

#0 Piwik\Error::errorHandler(...) called at [/home/duranseo/piwik/plugins/ExampleRssWidget/RssRenderer.php:60]
#1 Piwik\Plugins\ExampleRssWidget\RssRenderer->get(...) called at [/home/duranseo/piwik/plugins/ExampleRssWidget/Controller.php:25]
#2 Piwik\Plugins\ExampleRssWidget\Controller->rssPiwik(...) called at [:]
#3 call_user_func_array(...) called at [/home/duranseo/piwik/core/FrontController.php:521]
#4 Piwik\FrontController->doDispatch(...) called at [/home/duranseo/piwik/core/FrontController.php:84]
#5 Piwik\FrontController->dispatch(...) called at [/home/duranseo/piwik/core/dispatch.php:30]
#6 require_once(...) called at [/home/duranseo/piwik/index.php:47]