>>> [!note] Migrated issue <!-- Drupal.org comment --> <!-- Migrated from issue #3558456. --> Reported by: [beloglazov91](https://www.drupal.org/user/3431497) Related to !5 >>> <h3 id="summary-problem-motivation">Problem/Motivation</h3> <p>After upgrade to Drupal 10.5.6 the following Exception occurs for ajax-requests with Content-type: "application/json".</p> <blockquote><p>UnsupportedMediaTypeHttpException: No route found that matches "Content-Type: application/json" </p></blockquote> <h4 id="summary-steps-reproduce">Steps to reproduce</h4> <p>Install Drupal 10.5.6 and send ajax-request with "Content-Type: application/json" header.</p> <h3 id="summary-proposed-resolution">Proposed resolution</h3> <p>It happens because `rest_entity_recursive` module registers a new format "json_recursive" that automatically will be applied for requests with "Content-Type: application/json" header (<a href="https://git.drupalcode.org/project/rest_entity_recursive/-/blob/2.x/src/RestEntityRecursiveServiceProvider.php?ref_type=heads#L18">https://git.drupalcode.org/project/rest_entity_recursive/-/blob/2.x/src/RestEntityRecursiveServiceProvider.php?ref_type=heads#L18</a>). What is a source of this problem.</p> <p>It manages with http-foundation library and the logic of "format detector" has been updated 3 weeks ago (<a href="https://github.com/symfony/http-foundation/commit/ee93009480be472b3201ca9fbdc2fee3871985e3">https://github.com/symfony/http-foundation/commit/ee93009480be472b3201ca9fbdc2fee3871985e3</a>).</p> <p>It always returned "1st matched" format from the whole list unless these changes were applied. After that upgrade it returns "last matched" instead.</p> <p>Only one fix that should be applied - change expected "Content-type" for "application/json" format. Use "application/recursive-json" instead of "application/json".</p> <p>It's important to bear in mind that a certain "Content-type" should be used only once: "application/json" is already allocated for "json" format and it shouldn't be overridden by other formats unless we really want to override it (use a different handler).</p> <p>Right now to use "json_recursive" format, a user should pass "_format=json_recursive" in query string. With this fix - "Content-type: application/json-recursive" header will do the same and "json_recursive" format will not be used for requests with "Content-type: application/json" format.</p>