It's not necessary to set the variable inside the indexAction AND the WRAPPER because it's already a global variable which is set inside the public dependencies getEffectiveContainerParams Method. PHP: 'tosUrl' => XenForo_Dependencies_Public::getTosUrl() It's IMO even bad/causing problems, because my change of the variable on event container_public_params gets overwritten with this. I know i could change it via the acp options, but i need to change it via an addon. Edit: It's also happening inside of the XenForo_ControllerPublic_Register controller. Or is there another way to change it / or to remove it if necessary via an addon ?