Oh, wait, that image is of Webmin itself. That has nothing to do with SQL or caches.
If your server is actually down we can’t help you.
If it’s just Webmin that is down, login via ssh and check status of the webmin service and possibly restart the webmin service.
# systemctl status webmin
# systemctl restart webmin
If it fails, check /var/webmin/miniserv.error for why.