Getting an fatal error message when trying to render custom blocks on my node twig template
You can print blocks directly using Twig Tweak


  {# No need to configure this block on "admin/structure/block" page. #}
  &lt;dt&gt;Block:&lt;/dt&gt;
  &lt;dd&gt;{{ drupal_block('system_branding_block', {label: 'Branding', use_site_name: false}) }}&lt;/dd&gt;

  {# Bypass block.html.twig theming. #}
  &lt;dt&gt;Block (without wrapper):&lt;/dt&gt;
  &lt;dd&gt;{{ drupal_block('system_branding_block', wrapper=false) }}&lt;/dd&gt;



Source: Cheat sheet

Do not use the block's machine name, enable the devel and in block configuration click on Devel tab to get the Plugin ID.

For example, the Site Branding Block has machine name of sitebranding, but the plugin ID is system_branding_block