X_Y

I’ve done two tests, one making a purely clean installation(unzipped from wordpress download, empty database), one making an exact copy of the working site, neither worked. So it can only be a server related issue. I’m wondering if anybody had the similar issue before?

Ahh I see! That really helps a lot. However the first thing I get from google search is the approach above. And why not have custom post types activated by default?

I used it as described in the link above, in functions.php

add_filter('pll_get_post_types', 'my_pll_get_post_types');
function my_pll_get_post_types($types) {
	return array_merge($types, array('my-cpt' => 'my-cpt'));
}

Where my-cpt is my custom post type.