Invalid placeholder (!user) in string

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error.

Recent log messages show following two errors:

1. User error: Invalid placeholder (!user) in string: The Profile module provides a fieldable entity, that allows administrators to define different sets of fields for user profiles, which are then displayed in the My Account section. This permits users of a site to share more information about themselves, and can help community-based sites organize users around specific information. in Drupal\Component\Render\FormattableMarkup::placeholderFormat() (line 233 of /var/www/html/d8/docroot/core/lib/Drupal/Component/Render/FormattableMarkup.php).




2. Recoverable fatal error: Object of class Drupal\Core\Url could not be converted to string in Drupal\Component\Render\FormattableMarkup::placeholderFormat() (line 239 of /var/www/html/d8/docroot/core/lib/Drupal/Component/Render/FormattableMarkup.php).