WSOD when saving an assistant with an invalid model
>>> [!note] Migrated issue
<!-- Drupal.org comment -->
<!-- Migrated from issue #3504908. -->
Reported by: [andrewbelcher](https://www.drupal.org/user/655282)
Related to !693
>>>
<h3 id="summary-problem-motivation">Problem/Motivation</h3>
<p>I've got a site with the AWS Bedrock provider where my key doesn't have access to list models, so I get not list of models (probably should have a separate issue for handling that were models can be configured without that permission...).</p>
<p>Saving the AI Assistant form results in a WSOD:</p>
<pre>TypeError: Cannot assign null to property Drupal\ai_assistant_api\Entity\AiAssistant::$llm_model of type string in Drupal\Core\Config\Entity\ConfigEntityBase->set() (line 173 of core/lib/Drupal/Core/Config/Entity/ConfigEntityBase.php).</pre><h4 id="summary-steps-reproduce">Steps to reproduce</h4>
<h3 id="summary-proposed-resolution">Proposed resolution</h3>
<h3 id="summary-remaining-tasks">Remaining tasks</h3>
<h3 id="summary-ui-changes">User interface changes</h3>
<h3 id="summary-api-changes">API changes</h3>
<h3 id="summary-data-model-changes">Data model changes</h3>
issue