Call “the content” function problem

Hello, so I have two problems. The first one is that when I try to customize my website’s blog page with Elementor I get the message: “Sorry, the content area was not found in your page. You must call “the_content” function in the current template, in order for Elementor to work on this page.” I believe that I need to add: <?php the_content(); ?> in order for my blog page to work again. My problem is that I do not know exactly where to add this code (like which php file, and which line).

Another issue that I have is that I tried to troubleshoot, and I get his message:
“call_user_func_array() expects parameter 1 to be a valid callback, class ‘WP_Block_Supports’ not found in /home/customer/www/pourthatwine.com/public_html/wp-includes/class-wp-hook.php on line 287”

I have no idea whatsoever how to fix the second problem. I would really appreciate it if someone would help me with both problems. Thank you.