The provided host name is not valid for this server drupal 8 error [SOLVED]

You have not defined which url's are safe for your application.

Go to /sites/default/settings.php file and add these lines:

$settings['trusted_host_patterns'] = array(
  '^example\.com$',
  '^www\.example\.com$',
);
// change example.com to your domain

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Other snippets

Create or add a menu item without a link in drupal 8

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Increase the length of a custom entity name field in drupal 8 [SOLVED]

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