Methods with the same name as their class will not be constructors in a future version of PHP; Event_Notification has a deprecated constructor 
in '/home/kravmaga/domains/kravmagasaenstreek.nl/public_html/libs/Event/Notification.php' at the line 66

#0  Piwik_ErrorHandler(...) called at [/home/kravmaga/domains/kravmagasaenstreek.nl/public_html/core/Loader.php:91]
#1  require_once(...) called at [/home/kravmaga/domains/kravmagasaenstreek.nl/public_html/core/Loader.php:91]
#2  Piwik_Loader::loadClass(...) called at [/home/kravmaga/domains/kravmagasaenstreek.nl/public_html/core/Loader.php:109]
#3  Piwik_Loader::autoload(...) called at [:]
#4  spl_autoload_call(...) called at [/home/kravmaga/domains/kravmagasaenstreek.nl/public_html/core/PluginsManager.php:744]
#5  require_once(...) called at [/home/kravmaga/domains/kravmagasaenstreek.nl/public_html/core/FrontController.php:18]
#6  require_once(...) called at [/home/kravmaga/domains/kravmagasaenstreek.nl/public_html/core/Loader.php:72]
#7  Piwik_Loader::loadClass(...) called at [/home/kravmaga/domains/kravmagasaenstreek.nl/public_html/core/Loader.php:109]
#8  Piwik_Loader::autoload(...) called at [:]
#9  spl_autoload_call(...) called at [/home/kravmaga/domains/kravmagasaenstreek.nl/public_html/index.php:51]