diff -u b/core/modules/awesomplete_autocomplete/awesomplete_autocomplete.module b/core/modules/awesomplete_autocomplete/awesomplete_autocomplete.module
--- b/core/modules/awesomplete_autocomplete/awesomplete_autocomplete.module
+++ b/core/modules/awesomplete_autocomplete/awesomplete_autocomplete.module
@@ -15,7 +15,7 @@
     case 'help.page.awesomplete_autocomplete':
       $output = '<h3>' . t('About') . '</h3>';
       $output .= '<p>' . t('The Awesomplete Autocomplete module implements a replacement for jQuery UI Autocomplete. The asset library <code>core/jquery.ui.autocomplete</code> is deprecated in drupal:8.8.0 and is removed from drupal:9.0.0. Enabling this module overrides the current core asset library to evaluate Awesomplete and to assist with making any necessary style or API changes to themes or modules.') . '</p>';
-      $output .= '<p>' . t('For more information, see the <a href=":awesomplete_autocomplete">issue to replace jQuery UI Autocomplete</a>.', [':awesomplete_autocomplete' => 'https://www.drupal.org/project/drupal/issues/3076171']) . '</p>';
+      $output .= '<p>' . t('For more information, see the <a href=":awesomplete_autocomplete">online documentation for the Awesomplete Autocomplete module.</a>.', [':awesomplete_autocomplete' => 'https://www.drupal.org/docs/8/core/modules/experimental-awesomplete-autocomplete']) . '</p>';
       return $output;
   }
 }
@@ -25,8 +25,6 @@
  */
 function awesomplete_autocomplete_library_info_alter(&$libraries, $extension) {
   if ($extension == 'core' && isset($libraries['drupal.autocomplete'])) {
-    // Module full path.
-    $path = drupal_get_path('module', 'awesomplete_autocomplete') . '/js';
     // Remove core js.
     $libraries['drupal.autocomplete']['js'] = [];
     // Replace dependency.
diff -u b/core/modules/awesomplete_autocomplete/css/awesomplete.base.css b/core/modules/awesomplete_autocomplete/css/awesomplete.base.css
--- b/core/modules/awesomplete_autocomplete/css/awesomplete.base.css
+++ b/core/modules/awesomplete_autocomplete/css/awesomplete.base.css
@@ -1,33 +1,33 @@
 .awesomplete [hidden] {
-    display: none;
+  display: none;
 }
 
 .awesomplete .visually-hidden {
-    position: absolute;
-    clip: rect(0, 0, 0, 0);
+  position: absolute;
+  clip: rect(0, 0, 0, 0);
 }
 
 .awesomplete {
-    display: inline-block;
-    position: relative;
+  display: inline-block;
+  position: relative;
 }
 
 .awesomplete > input {
-    display: block;
+  display: block;
 }
 
 .awesomplete > ul {
-    position: absolute;
-    left: 0;
-    z-index: 1;
-    min-width: 100%;
-    box-sizing: border-box;
-    list-style: none;
-    padding: 0;
-    margin: 0;
-    background: #fff;
+  position: absolute;
+  left: 0;
+  z-index: 1;
+  min-width: 100%;
+  box-sizing: border-box;
+  list-style: none;
+  padding: 0;
+  margin: 0;
+  background: #fff;
 }
 
 .awesomplete > ul:empty {
-    display: none;
+  display: none;
 }
diff -u b/core/modules/awesomplete_autocomplete/js/autocomplete.es6.js b/core/modules/awesomplete_autocomplete/js/autocomplete.es6.js
--- b/core/modules/awesomplete_autocomplete/js/autocomplete.es6.js
+++ b/core/modules/awesomplete_autocomplete/js/autocomplete.es6.js
@@ -60,10 +60,14 @@
   /**
    * Return the id from a term value.
    *
-   * @param {string} term
-   * @returns {number}
+   * @param {object} term
+   *   A suggestion based on user input. It is an object with label and value
+   *   properties.
+   * @return {string}
+   *   The term id.
    */
-  const extractTermID = term => term.value.search(/\((\d+)\)$/);
+  const extractTermID = term =>
+    term.value ? term.value.search(/\((\d+)\)$/) : '';
 
   /**
    * Determines if a suggestion should be an available option.
@@ -127,7 +131,12 @@
    * @return {HTMLElement}
    *   A list element containing a suggestion.
    */
-  const displayItem = (suggestion, input) => Awesomplete.ITEM(suggestion, extractLastTerm(input), extractTermID(suggestion));
+  const displayItem = (suggestion, input) =>
+    Awesomplete.ITEM(
+      suggestion,
+      extractLastTerm(input),
+      extractTermID(suggestion),
+    );
 
   /**
    * Replaces the value of an input field when a new value is chosen.
diff -u b/core/modules/awesomplete_autocomplete/js/autocomplete.js b/core/modules/awesomplete_autocomplete/js/autocomplete.js
--- b/core/modules/awesomplete_autocomplete/js/autocomplete.js
+++ b/core/modules/awesomplete_autocomplete/js/autocomplete.js
@@ -40,7 +40,7 @@
   };
 
   var extractTermID = function extractTermID(term) {
-    return term.value.search(/\((\d+)\)$/);
+    return term.value ? term.value.search(/\((\d+)\)$/) : '';
   };
 
   function filterResults(suggestion, input) {
only in patch2:
unchanged:
--- a/core/tests/Drupal/Tests/Listeners/DeprecationListenerTrait.php
+++ b/core/tests/Drupal/Tests/Listeners/DeprecationListenerTrait.php
@@ -140,6 +140,7 @@ public static function getSkippedDeprecations() {
       // This deprecation comes from behat/mink-browserkit-driver when updating
       // symfony/browser-kit to 4.3+.
       'The "Symfony\Component\BrowserKit\Response::getStatus()" method is deprecated since Symfony 4.3, use getStatusCode() instead.',
+      'The "core/jquery.ui.autocomplete" asset library is deprecated in drupal:8.8.0 and is removed from drupal:9.0.0. See https://www.drupal.org/project/drupal/issues/3076171',
     ];
   }