Thank you for your reply. I am using www.soscisurvey.de.
Yesterday, some participants were unable to complete the survey due to an error. Since I cannot attach screenshots, I have transcribed the error messages below.
"Installation incomplete
“The installation is incomplete and therefore unavailable at the moment.”
→ Run Installation"
And the second error was:
“The setup has been completed. To enable the setup, either lock the server for maintenance or edit system/config.php, change the settings as follows:
$GLOBALS['oFb']['allow_setup'] = 'enabled';
After saving the edit, reload the page.”
The page also displayed “Contact Details” and “SoSci Survey GmbH, Impressum.”