Hi Ismael,
thank you for your reply. Yes, I have already taxonomy for it called “portfolio_category ” and it works. All changes to functionality is done via my own plugin. I added several post types, shortcodes etc. and it all works.
Now I have found a solution. I had to add a script to my plugin that enables search within defined post types:

add_filter( 'pre_get_posts', 'jetel_search' );
function jetel_search( $query ) {
	if ( $query->is_search ) {
		$query->set( 'post_type', array( 'post', 'page', 'kurz', 'lektor', 'portfolio' ) );
	}
	return $query;
	}

I have another question. How to limit a number of results in each category in instant search. Mean 3 results for pages, 3 for posts, 3 for courses…
And how to display similarly sorted results in page?

• This reply was modified 6 years, 11 months ago by jetel.

So there is a progress in my instalation. It worked until I created new page! It allowed one edit and now it is broken as well (sorry for not testing my previous solution deeply).

Otherwise I tried mrjukic solution and worked for me. Just open wp-config.php in your wordpress installation folder and add folowing row:

define( 'CONCATENATE_SCRIPTS', false );

Now the editor is finaly working as expected (no deep testing, just tried a little). Thanks mrjukic for advice!