fix #16002 (#16003)

1 files changed, 2 insertions, 2 deletions

diff --git a/plugins/CoreUpdater/Tasks.php b/plugins/CoreUpdater/Tasks.php
index f3ecae955d..4e313e6307 100644
--- a/plugins/CoreUpdater/Tasks.php
+++ b/plugins/CoreUpdater/Tasks.php
@@ -22,7 +22,7 @@ class Tasks extends \Piwik\Plugin\Tasks
         $dbSettings   = new \Piwik\Db\Settings();
         $settings = StaticContainer::get('Piwik\Plugins\CoreUpdater\SystemSettings');
 
-        if ($dbSettings->getUsedCharset() !== 'utf8mb4' && DbHelper::getDefaultCharset() === 'utf8mb4' && $settings->updateToUtf8mb4->getValue()) {
+        if ($dbSettings->getUsedCharset() !== 'utf8mb4' && DbHelper::getDefaultCharset() === 'utf8mb4' && !empty($settings->updateToUtf8mb4) && $settings->updateToUtf8mb4->getValue()) {
             $this->daily('convertToUtf8mb4', null, self::HIGHEST_PRIORITY);
         }
     }
@@ -50,4 +50,4 @@ class Tasks extends \Piwik\Plugin\Tasks
         $settings = StaticContainer::get('Piwik\Plugins\CoreUpdater\SystemSettings');
         $settings->updateToUtf8mb4->setValue(false);
     }
-}
\ No newline at end of file
+}