diff --git a/CRM/Donrec/Upgrader.php b/CRM/Donrec/Upgrader.php
index 181b721c..6ec80e4f 100644
--- a/CRM/Donrec/Upgrader.php
+++ b/CRM/Donrec/Upgrader.php
@@ -11,7 +11,7 @@
 /**
  * Collection of upgrade steps.
  */
-class CRM_Donrec_Upgrader extends CRM_Donrec_Upgrader_Base {
+class CRM_Donrec_Upgrader extends CRM_Extension_Upgrader_Base {
 
   // By convention, functions that look like "function upgrade_NNNN()" are
   // upgrade tasks. They are executed in order (like Drupal's hook_update_N).
diff --git a/CRM/Donrec/Upgrader/Base.php b/CRM/Donrec/Upgrader/Base.php
deleted file mode 100644
index c0657644..00000000
--- a/CRM/Donrec/Upgrader/Base.php
+++ /dev/null
@@ -1,376 +0,0 @@
-<?php
-
-// AUTO-GENERATED FILE -- Civix may overwrite any changes made to this file
-use CRM_Donrec_ExtensionUtil as E;
-
-/**
- * Base class which provides helpers to execute upgrade logic
- */
-class CRM_Donrec_Upgrader_Base {
-
-  /**
-   * @var varies, subclass of this
-   */
-  static $instance;
-
-  /**
-   * @var CRM_Queue_TaskContext
-   */
-  protected $ctx;
-
-  /**
-   * @var string, eg 'com.example.myextension'
-   */
-  protected $extensionName;
-
-  /**
-   * @var string, full path to the extension's source tree
-   */
-  protected $extensionDir;
-
-  /**
-   * @var array(revisionNumber) sorted numerically
-   */
-  private $revisions;
-
-  /**
-   * @var boolean
-   *   Flag to clean up extension revision data in civicrm_setting
-   */
-  private $revisionStorageIsDeprecated = FALSE;
-
-  /**
-   * Obtain a reference to the active upgrade handler.
-   */
-  static public function instance() {
-    if (!self::$instance) {
-      // FIXME auto-generate
-      self::$instance = new CRM_Donrec_Upgrader(
-        'de.systopia.donrec',
-        realpath(__DIR__ . '/../../../')
-      );
-    }
-    return self::$instance;
-  }
-
-  /**
-   * Adapter that lets you add normal (non-static) member functions to the queue.
-   *
-   * Note: Each upgrader instance should only be associated with one
-   * task-context; otherwise, this will be non-reentrant.
-   *
-   * @code
-   * CRM_Donrec_Upgrader_Base::_queueAdapter($ctx, 'methodName', 'arg1', 'arg2');
-   * @endcode
-   */
-  static public function _queueAdapter() {
-    $instance = self::instance();
-    $args = func_get_args();
-    $instance->ctx = array_shift($args);
-    $instance->queue = $instance->ctx->queue;
-    $method = array_shift($args);
-    return call_user_func_array(array($instance, $method), $args);
-  }
-
-  public function __construct($extensionName, $extensionDir) {
-    $this->extensionName = $extensionName;
-    $this->extensionDir = $extensionDir;
-  }
-
-  // ******** Task helpers ********
-
-  /**
-   * Run a CustomData file.
-   *
-   * @param string $relativePath the CustomData XML file path (relative to this extension's dir)
-   * @return bool
-   */
-  public function executeCustomDataFile($relativePath) {
-    $xml_file = $this->extensionDir . '/' . $relativePath;
-    return $this->executeCustomDataFileByAbsPath($xml_file);
-  }
-
-  /**
-   * Run a CustomData file
-   *
-   * @param string $xml_file  the CustomData XML file path (absolute path)
-   *
-   * @return bool
-   */
-  protected static function executeCustomDataFileByAbsPath($xml_file) {
-    $import = new CRM_Utils_Migrate_Import();
-    $import->run($xml_file);
-    return TRUE;
-  }
-
-  /**
-   * Run a SQL file.
-   *
-   * @param string $relativePath the SQL file path (relative to this extension's dir)
-   *
-   * @return bool
-   */
-  public function executeSqlFile($relativePath) {
-    CRM_Utils_File::sourceSQLFile(
-      CIVICRM_DSN,
-      $this->extensionDir . DIRECTORY_SEPARATOR . $relativePath
-    );
-    return TRUE;
-  }
-
-  /**
-   * @param string $tplFile
-   *   The SQL file path (relative to this extension's dir).
-   *   Ex: "sql/mydata.mysql.tpl".
-   * @return bool
-   */
-  public function executeSqlTemplate($tplFile) {
-    // Assign multilingual variable to Smarty.
-    $upgrade = new CRM_Upgrade_Form();
-
-    $tplFile = CRM_Utils_File::isAbsolute($tplFile) ? $tplFile : $this->extensionDir . DIRECTORY_SEPARATOR . $tplFile;
-    $smarty = CRM_Core_Smarty::singleton();
-    $smarty->assign('domainID', CRM_Core_Config::domainID());
-    CRM_Utils_File::sourceSQLFile(
-      CIVICRM_DSN, $smarty->fetch($tplFile), NULL, TRUE
-    );
-    return TRUE;
-  }
-
-  /**
-   * Run one SQL query.
-   *
-   * This is just a wrapper for CRM_Core_DAO::executeSql, but it
-   * provides syntatic sugar for queueing several tasks that
-   * run different queries
-   */
-  public function executeSql($query, $params = array()) {
-    // FIXME verify that we raise an exception on error
-    CRM_Core_DAO::executeQuery($query, $params);
-    return TRUE;
-  }
-
-  /**
-   * Syntatic sugar for enqueuing a task which calls a function in this class.
-   *
-   * The task is weighted so that it is processed
-   * as part of the currently-pending revision.
-   *
-   * After passing the $funcName, you can also pass parameters that will go to
-   * the function. Note that all params must be serializable.
-   */
-  public function addTask($title) {
-    $args = func_get_args();
-    $title = array_shift($args);
-    $task = new CRM_Queue_Task(
-      array(get_class($this), '_queueAdapter'),
-      $args,
-      $title
-    );
-    return $this->queue->createItem($task, array('weight' => -1));
-  }
-
-  // ******** Revision-tracking helpers ********
-
-  /**
-   * Determine if there are any pending revisions.
-   *
-   * @return bool
-   */
-  public function hasPendingRevisions() {
-    $revisions = $this->getRevisions();
-    $currentRevision = $this->getCurrentRevision();
-
-    if (empty($revisions)) {
-      return FALSE;
-    }
-    if (empty($currentRevision)) {
-      return TRUE;
-    }
-
-    return ($currentRevision < max($revisions));
-  }
-
-  /**
-   * Add any pending revisions to the queue.
-   */
-  public function enqueuePendingRevisions(CRM_Queue_Queue $queue) {
-    $this->queue = $queue;
-
-    $currentRevision = $this->getCurrentRevision();
-    foreach ($this->getRevisions() as $revision) {
-      if ($revision > $currentRevision) {
-        $title = ts('Upgrade %1 to revision %2', array(
-          1 => $this->extensionName,
-          2 => $revision,
-        ));
-
-        // note: don't use addTask() because it sets weight=-1
-
-        $task = new CRM_Queue_Task(
-          array(get_class($this), '_queueAdapter'),
-          array('upgrade_' . $revision),
-          $title
-        );
-        $this->queue->createItem($task);
-
-        $task = new CRM_Queue_Task(
-          array(get_class($this), '_queueAdapter'),
-          array('setCurrentRevision', $revision),
-          $title
-        );
-        $this->queue->createItem($task);
-      }
-    }
-  }
-
-  /**
-   * Get a list of revisions.
-   *
-   * @return array(revisionNumbers) sorted numerically
-   */
-  public function getRevisions() {
-    if (!is_array($this->revisions)) {
-      $this->revisions = array();
-
-      $clazz = new ReflectionClass(get_class($this));
-      $methods = $clazz->getMethods();
-      foreach ($methods as $method) {
-        if (preg_match('/^upgrade_(.*)/', $method->name, $matches)) {
-          $this->revisions[] = $matches[1];
-        }
-      }
-      sort($this->revisions, SORT_NUMERIC);
-    }
-
-    return $this->revisions;
-  }
-
-  public function getCurrentRevision() {
-    $revision = CRM_Core_BAO_Extension::getSchemaVersion($this->extensionName);
-    if (!$revision) {
-      $revision = $this->getCurrentRevisionDeprecated();
-    }
-    return $revision;
-  }
-
-  private function getCurrentRevisionDeprecated() {
-    $key = $this->extensionName . ':version';
-    if ($revision = CRM_Core_BAO_Setting::getItem('Extension', $key)) {
-      $this->revisionStorageIsDeprecated = TRUE;
-    }
-    return $revision;
-  }
-
-  public function setCurrentRevision($revision) {
-    CRM_Core_BAO_Extension::setSchemaVersion($this->extensionName, $revision);
-    // clean up legacy schema version store (CRM-19252)
-    $this->deleteDeprecatedRevision();
-    return TRUE;
-  }
-
-  private function deleteDeprecatedRevision() {
-    if ($this->revisionStorageIsDeprecated) {
-      $setting = new CRM_Core_BAO_Setting();
-      $setting->name = $this->extensionName . ':version';
-      $setting->delete();
-      CRM_Core_Error::debug_log_message("Migrated extension schema revision ID for {$this->extensionName} from civicrm_setting (deprecated) to civicrm_extension.\n");
-    }
-  }
-
-  // ******** Hook delegates ********
-
-  /**
-   * @see https://wiki.civicrm.org/confluence/display/CRMDOC/hook_civicrm_install
-   */
-  public function onInstall() {
-    $files = glob($this->extensionDir . '/sql/*_install.sql');
-    if (is_array($files)) {
-      foreach ($files as $file) {
-        CRM_Utils_File::sourceSQLFile(CIVICRM_DSN, $file);
-      }
-    }
-    $files = glob($this->extensionDir . '/sql/*_install.mysql.tpl');
-    if (is_array($files)) {
-      foreach ($files as $file) {
-        $this->executeSqlTemplate($file);
-      }
-    }
-    $files = glob($this->extensionDir . '/xml/*_install.xml');
-    if (is_array($files)) {
-      foreach ($files as $file) {
-        $this->executeCustomDataFileByAbsPath($file);
-      }
-    }
-    if (is_callable(array($this, 'install'))) {
-      $this->install();
-    }
-  }
-
-  /**
-   * @see https://wiki.civicrm.org/confluence/display/CRMDOC/hook_civicrm_postInstall
-   */
-  public function onPostInstall() {
-    $revisions = $this->getRevisions();
-    if (!empty($revisions)) {
-      $this->setCurrentRevision(max($revisions));
-    }
-    if (is_callable(array($this, 'postInstall'))) {
-      $this->postInstall();
-    }
-  }
-
-  /**
-   * @see https://wiki.civicrm.org/confluence/display/CRMDOC/hook_civicrm_uninstall
-   */
-  public function onUninstall() {
-    $files = glob($this->extensionDir . '/sql/*_uninstall.mysql.tpl');
-    if (is_array($files)) {
-      foreach ($files as $file) {
-        $this->executeSqlTemplate($file);
-      }
-    }
-    if (is_callable(array($this, 'uninstall'))) {
-      $this->uninstall();
-    }
-    $files = glob($this->extensionDir . '/sql/*_uninstall.sql');
-    if (is_array($files)) {
-      foreach ($files as $file) {
-        CRM_Utils_File::sourceSQLFile(CIVICRM_DSN, $file);
-      }
-    }
-  }
-
-  /**
-   * @see https://wiki.civicrm.org/confluence/display/CRMDOC/hook_civicrm_enable
-   */
-  public function onEnable() {
-    // stub for possible future use
-    if (is_callable(array($this, 'enable'))) {
-      $this->enable();
-    }
-  }
-
-  /**
-   * @see https://wiki.civicrm.org/confluence/display/CRMDOC/hook_civicrm_disable
-   */
-  public function onDisable() {
-    // stub for possible future use
-    if (is_callable(array($this, 'disable'))) {
-      $this->disable();
-    }
-  }
-
-  public function onUpgrade($op, CRM_Queue_Queue $queue = NULL) {
-    switch ($op) {
-      case 'check':
-        return array($this->hasPendingRevisions());
-
-      case 'enqueue':
-        return $this->enqueuePendingRevisions($queue);
-
-      default:
-    }
-  }
-
-}
diff --git a/donrec.civix.php b/donrec.civix.php
index 56f85dad..1cb3bbff 100644
--- a/donrec.civix.php
+++ b/donrec.civix.php
@@ -79,40 +79,22 @@ public static function findClass($suffix) {
 
 use CRM_Donrec_ExtensionUtil as E;
 
-function _donrec_civix_mixin_polyfill() {
-  if (!class_exists('CRM_Extension_MixInfo')) {
-    $polyfill = __DIR__ . '/mixin/polyfill.php';
-    (require $polyfill)(E::LONG_NAME, E::SHORT_NAME, E::path());
-  }
-}
-
 /**
  * (Delegated) Implements hook_civicrm_config().
  *
  * @link https://docs.civicrm.org/dev/en/latest/hooks/hook_civicrm_config
  */
-function _donrec_civix_civicrm_config(&$config = NULL) {
+function _donrec_civix_civicrm_config($config = NULL) {
   static $configured = FALSE;
   if ($configured) {
     return;
   }
   $configured = TRUE;
 
-  $template = CRM_Core_Smarty::singleton();
-
   $extRoot = __DIR__ . DIRECTORY_SEPARATOR;
-  $extDir = $extRoot . 'templates';
-
-  if (is_array($template->template_dir)) {
-    array_unshift($template->template_dir, $extDir);
-  }
-  else {
-    $template->template_dir = [$extDir, $template->template_dir];
-  }
-
   $include_path = $extRoot . PATH_SEPARATOR . get_include_path();
   set_include_path($include_path);
-  _donrec_civix_mixin_polyfill();
+  // Based on <compatibility>, this does not currently require mixin/polyfill.php.
 }
 
 /**
@@ -122,36 +104,7 @@ function _donrec_civix_civicrm_config(&$config = NULL) {
  */
 function _donrec_civix_civicrm_install() {
   _donrec_civix_civicrm_config();
-  if ($upgrader = _donrec_civix_upgrader()) {
-    $upgrader->onInstall();
-  }
-  _donrec_civix_mixin_polyfill();
-}
-
-/**
- * Implements hook_civicrm_postInstall().
- *
- * @link https://docs.civicrm.org/dev/en/latest/hooks/hook_civicrm_postInstall
- */
-function _donrec_civix_civicrm_postInstall() {
-  _donrec_civix_civicrm_config();
-  if ($upgrader = _donrec_civix_upgrader()) {
-    if (is_callable([$upgrader, 'onPostInstall'])) {
-      $upgrader->onPostInstall();
-    }
-  }
-}
-
-/**
- * Implements hook_civicrm_uninstall().
- *
- * @link https://docs.civicrm.org/dev/en/latest/hooks/hook_civicrm_uninstall
- */
-function _donrec_civix_civicrm_uninstall(): void {
-  _donrec_civix_civicrm_config();
-  if ($upgrader = _donrec_civix_upgrader()) {
-    $upgrader->onUninstall();
-  }
+  // Based on <compatibility>, this does not currently require mixin/polyfill.php.
 }
 
 /**
@@ -161,57 +114,7 @@ function _donrec_civix_civicrm_uninstall(): void {
  */
 function _donrec_civix_civicrm_enable(): void {
   _donrec_civix_civicrm_config();
-  if ($upgrader = _donrec_civix_upgrader()) {
-    if (is_callable([$upgrader, 'onEnable'])) {
-      $upgrader->onEnable();
-    }
-  }
-  _donrec_civix_mixin_polyfill();
-}
-
-/**
- * (Delegated) Implements hook_civicrm_disable().
- *
- * @link https://docs.civicrm.org/dev/en/latest/hooks/hook_civicrm_disable
- * @return mixed
- */
-function _donrec_civix_civicrm_disable(): void {
-  _donrec_civix_civicrm_config();
-  if ($upgrader = _donrec_civix_upgrader()) {
-    if (is_callable([$upgrader, 'onDisable'])) {
-      $upgrader->onDisable();
-    }
-  }
-}
-
-/**
- * (Delegated) Implements hook_civicrm_upgrade().
- *
- * @param $op string, the type of operation being performed; 'check' or 'enqueue'
- * @param $queue CRM_Queue_Queue, (for 'enqueue') the modifiable list of pending up upgrade tasks
- *
- * @return mixed
- *   based on op. for 'check', returns array(boolean) (TRUE if upgrades are pending)
- *   for 'enqueue', returns void
- *
- * @link https://docs.civicrm.org/dev/en/latest/hooks/hook_civicrm_upgrade
- */
-function _donrec_civix_civicrm_upgrade($op, CRM_Queue_Queue $queue = NULL) {
-  if ($upgrader = _donrec_civix_upgrader()) {
-    return $upgrader->onUpgrade($op, $queue);
-  }
-}
-
-/**
- * @return CRM_Donrec_Upgrader
- */
-function _donrec_civix_upgrader() {
-  if (!file_exists(__DIR__ . '/CRM/Donrec/Upgrader.php')) {
-    return NULL;
-  }
-  else {
-    return CRM_Donrec_Upgrader_Base::instance();
-  }
+  // Based on <compatibility>, this does not currently require mixin/polyfill.php.
 }
 
 /**
@@ -230,8 +133,8 @@ function _donrec_civix_insert_navigation_menu(&$menu, $path, $item) {
   if (empty($path)) {
     $menu[] = [
       'attributes' => array_merge([
-        'label'      => CRM_Utils_Array::value('name', $item),
-        'active'     => 1,
+        'label' => $item['name'] ?? NULL,
+        'active' => 1,
       ], $item),
     ];
     return TRUE;
@@ -295,14 +198,3 @@ function _donrec_civix_fixNavigationMenuItems(&$nodes, &$maxNavID, $parentID) {
     }
   }
 }
-
-/**
- * (Delegated) Implements hook_civicrm_entityTypes().
- *
- * Find any *.entityType.php files, merge their content, and return.
- *
- * @link https://docs.civicrm.org/dev/en/latest/hooks/hook_civicrm_entityTypes
- */
-function _donrec_civix_civicrm_entityTypes(&$entityTypes) {
-  $entityTypes = array_merge($entityTypes, []);
-}
diff --git a/donrec.php b/donrec.php
index c773da55..12be6cf3 100644
--- a/donrec.php
+++ b/donrec.php
@@ -29,13 +29,6 @@ function donrec_civicrm_install() {
   return _donrec_civix_civicrm_install();
 }
 
-/**
- * Implementation of hook_civicrm_uninstall
- */
-function donrec_civicrm_uninstall() {
-  return _donrec_civix_civicrm_uninstall();
-}
-
 /**
  * Implementation of hook_civicrm_enable
  */
@@ -43,26 +36,6 @@ function donrec_civicrm_enable() {
   return _donrec_civix_civicrm_enable();
 }
 
-/**
- * Implementation of hook_civicrm_disable
- */
-function donrec_civicrm_disable() {
-  return _donrec_civix_civicrm_disable();
-}
-
-/**
- * Implementation of hook_civicrm_upgrade
- *
- * @param $op string, the type of operation being performed; 'check' or 'enqueue'
- * @param $queue CRM_Queue_Queue, (for 'enqueue') the modifiable list of pending up upgrade tasks
- *
- * @return mixed  based on op. for 'check', returns array(boolean) (TRUE if upgrades are pending)
- *                for 'enqueue', returns void
- */
-function donrec_civicrm_upgrade($op, CRM_Queue_Queue $queue = NULL) {
-  return _donrec_civix_civicrm_upgrade($op, $queue);
-}
-
 /**
 * Add an action for creating donation receipts after doing a search
 *
@@ -601,15 +574,6 @@ function donrec_civicrm_buildForm($formName, &$form) {
   }
 }
 
-/**
- * Implements hook_civicrm_postInstall().
- *
- * @link https://docs.civicrm.org/dev/en/latest/hooks/hook_civicrm_postInstall
- */
-function donrec_civicrm_postInstall() {
-  _donrec_civix_civicrm_postInstall();
-}
-
 // /**
 //  * Implements hook_civicrm_entityTypes().
 //  *
diff --git a/info.xml b/info.xml
index 602ca39d..c1792a11 100644
--- a/info.xml
+++ b/info.xml
@@ -12,7 +12,6 @@
   <version>2.2-dev</version>
   <develStage>dev</develStage>
   <compatibility>
-    <ver>5.2</ver>
     <ver>5.60</ver>
   </compatibility>
   <urls>
@@ -20,16 +19,19 @@
     <url desc="Documentation">http://wiki.civicrm.org/confluence/display/CRM/DonationReceipts+Extension</url>
     <url desc="Support">https://github.com/systopia/de.systopia.donrec/issues</url>
   </urls>
-  <comments>Developed by SYSTOPIA. Thanks to Niko Bochan, Thomas Leichtfuß and Björn Endres.</comments>
+  <comments>Developed by SYSTOPIA. Thanks to Niko Bochan, Thomas Leichtfu&#xDF; and Bj&#xF6;rn Endres.</comments>
   <civix>
     <namespace>CRM/Donrec</namespace>
-    <format>22.10.0</format>
+    <format>23.02.1</format>
   </civix>
   <mixins>
     <mixin>menu-xml@1.0.0</mixin>
     <mixin>setting-php@1.0.0</mixin>
+    <mixin>smarty-v2@1.0.1</mixin>
   </mixins>
   <classloader>
     <psr0 prefix="CRM_" path="."/>
+    <psr4 prefix="Civi\" path="Civi"/>
   </classloader>
+  <upgrader>CRM_Donrec_Upgrader</upgrader>
 </extension>
diff --git a/mixin/menu-xml@1.0.0.mixin.php b/mixin/menu-xml@1.0.0.mixin.php
deleted file mode 100644
index 4c0b2276..00000000
--- a/mixin/menu-xml@1.0.0.mixin.php
+++ /dev/null
@@ -1,31 +0,0 @@
-<?php
-
-/**
- * Auto-register "xml/Menu/*.xml" files.
- *
- * @mixinName menu-xml
- * @mixinVersion 1.0.0
- *
- * @param CRM_Extension_MixInfo $mixInfo
- *   On newer deployments, this will be an instance of MixInfo. On older deployments, Civix may polyfill with a work-a-like.
- * @param \CRM_Extension_BootCache $bootCache
- *   On newer deployments, this will be an instance of MixInfo. On older deployments, Civix may polyfill with a work-a-like.
- */
-return function ($mixInfo, $bootCache) {
-
-  /**
-   * @param \Civi\Core\Event\GenericHookEvent $e
-   * @see CRM_Utils_Hook::xmlMenu()
-   */
-  Civi::dispatcher()->addListener('hook_civicrm_xmlMenu', function ($e) use ($mixInfo) {
-    if (!$mixInfo->isActive()) {
-      return;
-    }
-
-    $files = (array) glob($mixInfo->getPath('xml/Menu/*.xml'));
-    foreach ($files as $file) {
-      $e->files[] = $file;
-    }
-  });
-
-};
diff --git a/mixin/polyfill.php b/mixin/polyfill.php
deleted file mode 100644
index f57c5ebb..00000000
--- a/mixin/polyfill.php
+++ /dev/null
@@ -1,101 +0,0 @@
-<?php
-
-/**
- * When deploying on systems that lack mixin support, fake it.
- *
- * @mixinFile polyfill.php
- *
- * This polyfill does some (persnickity) deduplication, but it doesn't allow upgrades or shipping replacements in core.
- *
- * Note: The polyfill.php is designed to be copied into extensions for interoperability. Consequently, this file is
- * not used 'live' by `civicrm-core`. However, the file does need a canonical home, and it's convenient to keep it
- * adjacent to the actual mixin files.
- *
- * @param string $longName
- * @param string $shortName
- * @param string $basePath
- */
-return function ($longName, $shortName, $basePath) {
-  // Construct imitations of the mixin services. These cannot work as well (e.g. with respect to
-  // number of file-reads, deduping, upgrading)... but they should be OK for a few months while
-  // the mixin services become available.
-
-  // List of active mixins; deduped by version
-  $mixinVers = [];
-  foreach ((array) glob($basePath . '/mixin/*.mixin.php') as $f) {
-    [$name, $ver] = explode('@', substr(basename($f), 0, -10));
-    if (!isset($mixinVers[$name]) || version_compare($ver, $mixinVers[$name], '>')) {
-      $mixinVers[$name] = $ver;
-    }
-  }
-  $mixins = [];
-  foreach ($mixinVers as $name => $ver) {
-    $mixins[] = "$name@$ver";
-  }
-
-  // Imitate CRM_Extension_MixInfo.
-  $mixInfo = new class() {
-
-    /**
-     * @var string
-     */
-    public $longName;
-
-    /**
-     * @var string
-     */
-    public $shortName;
-
-    public $_basePath;
-
-    public function getPath($file = NULL) {
-      return $this->_basePath . ($file === NULL ? '' : (DIRECTORY_SEPARATOR . $file));
-    }
-
-    public function isActive() {
-      return \CRM_Extension_System::singleton()->getMapper()->isActiveModule($this->shortName);
-    }
-
-  };
-  $mixInfo->longName = $longName;
-  $mixInfo->shortName = $shortName;
-  $mixInfo->_basePath = $basePath;
-
-  // Imitate CRM_Extension_BootCache.
-  $bootCache = new class() {
-
-    public function define($name, $callback) {
-      $envId = \CRM_Core_Config_Runtime::getId();
-      $oldExtCachePath = \Civi::paths()->getPath("[civicrm.compile]/CachedExtLoader.{$envId}.php");
-      $stat = stat($oldExtCachePath);
-      $file = Civi::paths()->getPath('[civicrm.compile]/CachedMixin.' . md5($name . ($stat['mtime'] ?? 0)) . '.php');
-      if (file_exists($file)) {
-        return include $file;
-      }
-      else {
-        $data = $callback();
-        file_put_contents($file, '<' . "?php\nreturn " . var_export($data, 1) . ';');
-        return $data;
-      }
-    }
-
-  };
-
-  // Imitate CRM_Extension_MixinLoader::run()
-  // Parse all live mixins before trying to scan any classes.
-  global $_CIVIX_MIXIN_POLYFILL;
-  foreach ($mixins as $mixin) {
-    // If the exact same mixin is defined by multiple exts, just use the first one.
-    if (!isset($_CIVIX_MIXIN_POLYFILL[$mixin])) {
-      $_CIVIX_MIXIN_POLYFILL[$mixin] = include_once $basePath . '/mixin/' . $mixin . '.mixin.php';
-    }
-  }
-  foreach ($mixins as $mixin) {
-    // If there's trickery about installs/uninstalls/resets, then we may need to register a second time.
-    if (!isset(\Civi::$statics[__FUNCTION__][$mixin])) {
-      \Civi::$statics[__FUNCTION__][$mixin] = 1;
-      $func = $_CIVIX_MIXIN_POLYFILL[$mixin];
-      $func($mixInfo, $bootCache);
-    }
-  }
-};
diff --git a/mixin/setting-php@1.0.0.mixin.php b/mixin/setting-php@1.0.0.mixin.php
deleted file mode 100644
index 7195af40..00000000
--- a/mixin/setting-php@1.0.0.mixin.php
+++ /dev/null
@@ -1,32 +0,0 @@
-<?php
-
-/**
- * Auto-register "settings/*.setting.php" files.
- *
- * @mixinName setting-php
- * @mixinVersion 1.0.0
- *
- * @param CRM_Extension_MixInfo $mixInfo
- *   On newer deployments, this will be an instance of MixInfo. On older deployments, Civix may polyfill with a work-a-like.
- * @param \CRM_Extension_BootCache $bootCache
- *   On newer deployments, this will be an instance of MixInfo. On older deployments, Civix may polyfill with a work-a-like.
- */
-return function ($mixInfo, $bootCache) {
-
-  /**
-   * @param \Civi\Core\Event\GenericHookEvent $e
-   * @see CRM_Utils_Hook::alterSettingsFolders()
-   */
-  Civi::dispatcher()->addListener('hook_civicrm_alterSettingsFolders', function ($e) use ($mixInfo) {
-    // When deactivating on a polyfill/pre-mixin system, listeners may not cleanup automatically.
-    if (!$mixInfo->isActive()) {
-      return;
-    }
-
-    $settingsDir = $mixInfo->getPath('settings');
-    if (!in_array($settingsDir, $e->settingsFolders) && is_dir($settingsDir)) {
-      $e->settingsFolders[] = $settingsDir;
-    }
-  });
-
-};