Call to a member function isTranslatable() on null in Drupal\link\Plugin\Field\FieldWidget\LinkWidget::getUserEnteredStringAsUri() (line 119 of /var/www/html/docroot/core/modules/link/src/Plugin/Field/FieldWidget/LinkWidget.php)

There is not a patch.

Some research will be needed to figure out why the value is null, so we aren't masking a larger issue.

Until then, if someone has this issue with Drupal core version 10.1.7, this patch could help.

Fine to post but this is not ready for review yet. Certainly can’t be committed yet

The modified patch checks if the $node object is not null and if it's an instance of the expected class (ObjectClass).
The check for translatability is simplified to directly use the $node object. If it's not null and is translatable, it returns the internal URI; otherwise, it returns the original URI.