diff -u b/core/modules/system/src/Form/ModulesListForm.php b/core/modules/system/src/Form/ModulesListForm.php
--- b/core/modules/system/src/Form/ModulesListForm.php
+++ b/core/modules/system/src/Form/ModulesListForm.php
@@ -147,7 +147,7 @@
       uasort($modules, 'system_sort_modules_by_info_name');
     }
     catch (InfoParserException $e) {
-      $this->messenger()->addError($this->t('Modules could not be listed due to an error: "%error"', ['%error' => $e->getMessage()]));
+      $this->messenger()->addError($this->t(Modules can not be listed due to an error: %error, [%error => $e->getMessage()]));
       $modules = [];
     }