Thank you VoiD2008.
I don’t have any other plugins, but I added some lines (see below) to functions.php myself, in order to get the custom post types displayed in the main query.
I commented this out and all was normal again.
But still, I need the functionality of the code snippet. Any ideas?
This was the code that provoked the problem:
add_action( 'pre_get_posts', 'add_my_post_types_to_query' );
function add_my_post_types_to_query( $query ) {
if ($query->is_main_query() )
$query->set( 'post_type', array('commissionedproject', 'alexaproject') );
return $query;
}