I have two problems with the Blog page.:

1. I chose Gird 3 columns to be post page. But when I chose it my blog isn't in grid 3 columns. 

2. When I chose Breadcrumb Background Image nothing change.

I will be very glad if you can help me with this issues.

Hello, Kevin!

Thank you very much! It's okay now. Can you also tell me why I can't use Blog Detailed sidebar. I think it will be better to make it 2 columns with Blog Detailed sidebar, but when I chose this widget on Left Sidebar on Page layout options, nothing happens, also in Appearance -> Widgets it appears that I have inactive sidebar (these inactive sidebars are included in Blog Detailed Sidebar Widget. How can I add this widget?

Hello!

I don't understand what I have to open. WordPress Editor do you mean?

Hello!

I don't have Appearance -> editor in my dashboard. I searched for this problem in google. In most videos and forums people says to change one code to false. But I don't have this code, so I tried to add it in wp-config.php file, but nothing happened. The code is:

define('DISALLOW_FILE_EDIT', true);

Is it right to add this code?