diff --git a/core/lib/Drupal/Core/Config/ConfigInstaller.php b/core/lib/Drupal/Core/Config/ConfigInstaller.php
index 1b68a40..89cee73 100644
--- a/core/lib/Drupal/Core/Config/ConfigInstaller.php
+++ b/core/lib/Drupal/Core/Config/ConfigInstaller.php
@@ -460,12 +460,9 @@ public function checkConfigurationToInstall($type, $name) {
     if (!empty($invalid_default_config)) {
       $missing = [];
       foreach ($missing_dependencies as $dependent => $dependencies) {
-        $missing = array_merge($missing, $dependencies);
+        $missing[$dependent] = $dependencies;
       }
-      if ($missing) {
-        $missing = array_unique($missing);
-      }
-      throw UnmetDependenciesException::create($name, $invalid_default_config, $missing);
+      throw UnmetDependenciesException::create($name, array_unique($missing));
     }
 
     // Install profiles can not have config clashes. Configuration that
@@ -501,7 +498,7 @@ public function checkConfigurationToInstall($type, $name) {
   protected function findDefaultConfigWithUnmetDependencies(StorageInterface $storage, array $enabled_extensions, array $profile_storages = [], array &$missing_dependencies = []) {
     $config_to_create = $this->getConfigToCreate($storage, StorageInterface::DEFAULT_COLLECTION, '', $profile_storages);
     $all_config = array_merge($this->configFactory->listAll(), array_keys($config_to_create));
-    return array_filter(array_keys($config_to_create), function($config_name) use ($enabled_extensions, $all_config, $config_to_create, $missing_dependencies) {
+    return array_filter(array_keys($config_to_create), function($config_name) use ($enabled_extensions, $all_config, $config_to_create, &$missing_dependencies) {
       $missing = $this->getMissingDependencies($config_name, $config_to_create[$config_name], $enabled_extensions, $all_config);
       if ($missing) {
         $missing_dependencies[$config_name] = $missing;
diff --git a/core/lib/Drupal/Core/Config/UnmetDependenciesException.php b/core/lib/Drupal/Core/Config/UnmetDependenciesException.php
index fd2b63f..5d0cfb1 100644
--- a/core/lib/Drupal/Core/Config/UnmetDependenciesException.php
+++ b/core/lib/Drupal/Core/Config/UnmetDependenciesException.php
@@ -53,12 +53,10 @@ public function getExtension() {
    * @return string
    */
   public function getTranslatedMessage(TranslationInterface $string_translation, $extension) {
-    return $string_translation->formatPlural(
-      count($this->getConfigObjects()),
-      'Unable to install @extension, %config_names has unmet dependencies.',
-      'Unable to install @extension, %config_names have unmet dependencies.',
+    return $string_translation->translate(
+      'Unable to install @extension due to unmet dependencies: @config_names',
       [
-        '%config_names' => implode(', ', $this->getConfigObjects()),
+        '@config_names' => self::formatConfigObjectList($this->configObjects),
         '@extension' => $extension,
       ]
     );
@@ -70,18 +68,16 @@ public function getTranslatedMessage(TranslationInterface $string_translation, $
    * @param $extension
    *   The name of the extension that is being installed.
    * @param array $config_objects
-   *   A list of configuration object names that have unmet dependencies
-   * @param array $missing_dependencies
-   *   (optional) The list of missing dependencies.
+   *   A list of configuration keyed by configuration name, with unmet
+   *   dependencies as the value.
    *
    * @return \Drupal\Core\Config\PreExistingConfigException
    */
-  public static function create($extension, array $config_objects, array $missing_dependencies = []) {
-    $message = SafeMarkup::format('Configuration objects (@config_names) provided by @extension have unmet dependencies: @dependencies',
+  public static function create($extension, array $config_objects) {
+    $message = SafeMarkup::format('Configuration objects provided by @extension have unmet dependencies: @config_names',
       array(
-        '@config_names' => implode(', ', $config_objects),
-        '@extension' => $extension,
-        '@dependencies' => implode(', ', $missing_dependencies),
+        '@config_names' => static::formatConfigObjectList($config_objects),
+        '@extension' => $extension
       )
     );
     $e = new static($message);
@@ -90,4 +86,21 @@ public static function create($extension, array $config_objects, array $missing_
     return $e;
   }
 
+  /**
+   * Formats a list of configuration objects.
+   *
+   * @param array $config_objects
+   *   A list of configuration object names that have unmet dependencies.
+   *
+   * @return string
+   *   The imploded config_objects, formatted in an easy to read string.
+   */
+  protected static function formatConfigObjectList(array $config_objects) {
+    $list = [];
+    foreach ($config_objects as $config_object => $missing_dependencies) {
+      $list[] = $config_object . ' (' . implode(', ', $missing_dependencies) . ')';
+    }
+    return implode(', ', $list);
+  }
+
 }
diff --git a/core/modules/config/src/Tests/ConfigInstallProfileUnmetDependenciesTest.php b/core/modules/config/src/Tests/ConfigInstallProfileUnmetDependenciesTest.php
index 3371198..cfebbb6 100644
--- a/core/modules/config/src/Tests/ConfigInstallProfileUnmetDependenciesTest.php
+++ b/core/modules/config/src/Tests/ConfigInstallProfileUnmetDependenciesTest.php
@@ -90,7 +90,7 @@ public function testInstalled() {
     else {
       $this->fail('Expected Drupal\Core\Config\UnmetDependenciesException exception thrown');
     }
-    $this->assertErrorLogged('Configuration objects (system.action.user_block_user_action) provided by user have unmet dependencies in');
+    $this->assertErrorLogged('Configuration objects provided by user have unmet dependencies: system.action.user_block_user_action (action)');
   }
 
 }
diff --git a/core/modules/config/src/Tests/ConfigInstallWebTest.php b/core/modules/config/src/Tests/ConfigInstallWebTest.php
index 083b123..6c3be10 100644
--- a/core/modules/config/src/Tests/ConfigInstallWebTest.php
+++ b/core/modules/config/src/Tests/ConfigInstallWebTest.php
@@ -180,7 +180,7 @@ public function testUnmetDependenciesInstall() {
     // not depend on config_test and order is important.
     $this->drupalPostForm('admin/modules', array('modules[Testing][config_test][enable]' => TRUE), t('Install'));
     $this->drupalPostForm('admin/modules', array('modules[Testing][config_install_dependency_test][enable]' => TRUE), t('Install'));
-    $this->assertRaw('Unable to install Config install dependency test, <em class="placeholder">config_other_module_config_test.weird_simple_config, config_test.dynamic.other_module_test_with_dependency</em> have unmet dependencies.');
+    $this->assertRaw('Unable to install Config install dependency test due to unmet dependencies: config_test.dynamic.other_module_test_with_dependency (config_other_module_config_test)');
 
     $this->drupalPostForm('admin/modules', array('modules[Testing][config_other_module_config_test][enable]' => TRUE), t('Install'));
     $this->drupalPostForm('admin/modules', array('modules[Testing][config_install_dependency_test][enable]' => TRUE), t('Install'));
diff --git a/core/modules/simpletest/src/TestBase.php b/core/modules/simpletest/src/TestBase.php
index 4258f80..c2b53ad 100644
--- a/core/modules/simpletest/src/TestBase.php
+++ b/core/modules/simpletest/src/TestBase.php
@@ -830,7 +830,7 @@ protected function assertErrorLogged($error_message) {
     }
 
     $content = file_get_contents($error_log_filename);
-    $rows = explode(PHP_EOL, $content);
+     $rows = explode(PHP_EOL, $content);
 
     // We iterate over the rows in order to be able to remove the logged error
     // afterwards.