diff --git a/src/Classes/Notification.php b/src/Classes/Notification.php
index 46776c38..e787c919 100644
--- a/src/Classes/Notification.php
+++ b/src/Classes/Notification.php
@@ -15,6 +15,9 @@
 
 class Notification
 {
+    public const TYPE_ERROR = 'error';
+    public const TYPE_WARNING = 'warning';
+
     private const MMLC_SESSION_NAME = 'mmlc';
 
     /**
diff --git a/src/Classes/SelfUpdater.php b/src/Classes/SelfUpdater.php
index bfe15cbe..9115e9be 100644
--- a/src/Classes/SelfUpdater.php
+++ b/src/Classes/SelfUpdater.php
@@ -21,6 +21,8 @@
 use RobinTheHood\ModifiedModuleLoaderClient\Api\V1\HttpRequest;
 use RobinTheHood\ModifiedModuleLoaderClient\Semver\Filter;
 use RobinTheHood\ModifiedModuleLoaderClient\Semver\Sorter;
+use RuntimeException;
+use Throwable;
 
 class SelfUpdater
 {
@@ -98,13 +100,20 @@ public function update(MmlcVersionInfo $mmlcVersionInfo): void
 
         $this->createRestore($mmlcVersionInfo);
         $this->download($mmlcVersionInfo);
-        $this->backup($mmlcVersionInfo);
         $this->untar($mmlcVersionInfo);
         $this->verifyUntar($mmlcVersionInfo);
-        $this->install($mmlcVersionInfo);
-        $this->setupConfig($mmlcVersionInfo);
-        $this->setupVersion($mmlcVersionInfo);
-        $this->verifyUpdate($mmlcVersionInfo);
+
+        $check = $this->systemCheck($mmlcVersionInfo);
+
+        if ($check) {
+            $this->backup($mmlcVersionInfo);
+            $this->install($mmlcVersionInfo);
+            $this->setupConfig($mmlcVersionInfo);
+            $this->setupVersion($mmlcVersionInfo);
+            $this->verifyUpdate($mmlcVersionInfo);
+        }
+
+        $this->remove($mmlcVersionInfo);
         $this->removeRestore($mmlcVersionInfo);
 
         opcache_reset();
@@ -216,7 +225,11 @@ private function install(MmlcVersionInfo $mmlcVersionInfo): void
 
         $files = FileHelper::scanDir($srcPath, FileHelper::FILES_AND_DIRS, true);
         FileHelper::moveFilesTo($files, $srcPath, $destPath);
+    }
 
+    private function remove(MmlcVersionInfo $mmlcVersionInfo): void
+    {
+        $srcPath = $this->appRoot . '/ModifiedModuleLoaderClient';
         system('rm -rf ' . $srcPath);
     }
 
@@ -285,6 +298,53 @@ private function verifyUpdate(MmlcVersionInfo $mmlcVersionInfo): bool
         return true;
     }
 
+    private function systemCheck(MmlcVersionInfo $mmlcVersionInfo): bool
+    {
+        try {
+            $systemCheck = $this->getSystemCheckObj();
+            $check = $systemCheck->check();
+            if ($check['result'] === 'passed') {
+                return true;
+            } else {
+                Notification::pushFlashMessage([
+                    'text' => "Update canceled - Can not update MMLC. Not all system requirements are met.<br>\n"
+                    . json_encode($check['checks'], JSON_PRETTY_PRINT),
+                    'type' => Notification::TYPE_ERROR
+                ]);
+            }
+        } catch (RuntimeException $e) {
+            Notification::pushFlashMessage([
+                'text' => "Update canceled - " . $e->getMessage(),
+                'type' => Notification::TYPE_ERROR
+            ]);
+        }
+
+        return false;
+    }
+
+    private function getSystemCheckObj()
+    {
+        $systemCheckFilePath = $this->appRoot . '/ModifiedModuleLoaderClient/src/Classes/SystemCheck.php';
+        // $systemCheckFilePath = $this->appRoot . '/src/Classes/SystemCheck.php'; // Für Testzwecke
+
+        if (!file_exists($systemCheckFilePath)) {
+            throw new RuntimeException("Can not find file $systemCheckFilePath in downloaded .tar file");
+        }
+
+        try {
+            $fileContent = file_get_contents($systemCheckFilePath);
+            $fileContent = str_replace('class SystemCheck', 'class SystemCheckNew', $fileContent);
+            $fileContent = str_replace('<?php', '', $fileContent);
+
+            eval($fileContent);
+
+            $classSystemCheckNew = 'RobinTheHood\ModifiedModuleLoaderClient\SystemCheckNew';
+            return new $classSystemCheckNew();
+        } catch (Throwable $t) {
+            throw new RuntimeException("Can not load file $systemCheckFilePath");
+        }
+    }
+
     private function postUpdateSteps(): void
     {
         // Vor der Version 1.12.0 haben sich die config.php und die version.json
diff --git a/src/Classes/SystemCheck.php b/src/Classes/SystemCheck.php
new file mode 100644
index 00000000..707c28f0
--- /dev/null
+++ b/src/Classes/SystemCheck.php
@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of MMLC - ModifiedModuleLoaderClient.
+ *
+ * (c) Robin Wieschendorf <mail@robinwieschendorf.de>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace RobinTheHood\ModifiedModuleLoaderClient;
+
+class SystemCheck
+{
+    public const RESULT_PASSED = 'passed';
+    public const RESULT_FAILED = 'failed';
+
+    public const REQUIRED_PHP_VERSION = '7.4.0';
+
+    public function check(array $options = []): array
+    {
+        $php = [
+            'is' => PHP_VERSION,
+            'require' => '>=' . self::REQUIRED_PHP_VERSION,
+        ];
+
+        if (version_compare(PHP_VERSION, self::REQUIRED_PHP_VERSION, '<')) {
+            $php['result'] = self::RESULT_FAILED;
+            $result = self::RESULT_FAILED;
+        } else {
+            $php['result'] = self::RESULT_PASSED;
+            $result = self::RESULT_PASSED;
+        }
+
+        return [
+            'result' => $result,
+            'checks' => [
+                'php' =>  $php
+            ]
+        ];
+    }
+}
diff --git a/src/Templates/SelfUpdate.tmpl.php b/src/Templates/SelfUpdate.tmpl.php
index 206d3eb4..d5094d1f 100644
--- a/src/Templates/SelfUpdate.tmpl.php
+++ b/src/Templates/SelfUpdate.tmpl.php
@@ -2,7 +2,9 @@
 defined('LOADED_FROM_INDEX') && LOADED_FROM_INDEX ?? die('Access denied.');
 
 use RobinTheHood\ModifiedModuleLoaderClient\Config;
+use RobinTheHood\ModifiedModuleLoaderClient\ViewModels\NotificationViewModel;
 
+$notificationView = new NotificationViewModel();
 ?>
 
 <!DOCTYPE html>
@@ -15,6 +17,8 @@
         <?php include 'Navi.tmpl.php' ?>
 
         <div class="content" style="text-align: center">
+            <?= $notificationView->renderFlashMessages() ?>
+
             <div class="self-update">
                 <h2>MMLC - Modified Module Loader Client</h2>
                 <?= $installedVersionString ?><br><br>