Zitat (axel.hoercher)[lvphg] [2019-06-17 11:22:23.538114] vtc_root.ERROR: ilErrorHandling::{closure}:50 2 count(): Parameter must be an array or an object that implements Countable in /var/www/html/ilias/Modules/LearningModule/classes/class.ilContObjParser.php:1213
It looks like this is a known issue in ILIAS 5.4.2 with PHP 7.2:
https://mantis.ilias.de/view.php?id=25433
There is currently no solution yet. As a workaround, you could try using an older version of PHP (e.g. PHP 7.0 or 7.1).