Error
“Declaration of Concrete\Package\Zoomer\Block\Zoomer\Controller::registerViewAssets() should be compatible with Concrete\Core\Block\BlockController::registerViewAssets($outputContent = ”)”
in controller.php
erstat
public function registerViewAssets()
med
public function registerViewAssets($outputContent = '')
https://www.concrete5.org/community/forums/5-7-discussion/php7-issues/#818639