Error in PHP 7.2: Parameter must be an array or an object

Hi

In PHP 7.2.2 i get the following error:

Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\site\wp-includes\media.php on line 1206

From another thread, I could see that the user got the problem down to the "blog" GP premium plugin.

When I disabled the "blog" feature from GeneratePress, my error messages disappeared as well.

I am using the latest version of Wordpress (4.9.4) and latest version of GeneratePress and GP Premium.

The error messages appears above all media, even on content-single.php.