i made a duplicate of my live website here: (see url)
and noticed that there are errors on the homepage and also on some of the other pages:
Warning: count(): Parameter must be an array or an object that implements Countable in /www/htdocs/w012be4d/neu.netzspinnerei.at/wp-includes/media.php on line 1206
I deactivated all plugins and reactivated one by one and it seems that the error comes from gp-premium. I also deactivated all the modules on gp-premium and reactivated them – it seems the “blog” module causes the error.