try to use console button

app/UI/Vms/Pages/VmsDataTable.php

@@ -84,7 +84,7 @@ class VmsDataTable extends DataTable implements ClientArea, AdminArea
         if (isAdmin() || $this->configuration()->isPermissionNovnc()){
             //console
             $this->addActionButton(new ConsoleButton());
-            $consoleUrl = "https://www.symbionet.de";
+            $consoleUrl = "http://www.symbionet.de";
             $this->actionButtons['consoleButton']->setConsoleUrl($consoleUrl);
         }
         if(!$isAdmin){