Hello Bro.
I guessed where the mistake came from.
By inserting a code for adsense I removed a whole line of the original code. Specifically
<div id=”primary” <?php generate_do_element_classes( ‘content’ ); ?>>
In the single.php template
I’ve reset it and everything works great.
I’m studying to become a theme premium, since it’s worth it.
Thank you for the answers, a greeting to all.