If you do not want this error to happen, you will either need to purchase and install a commercially-signed SSL certificate onto the SSL-VPN appliance, or follow the suggested workarounds below. The connection between your browser and the appliance will still be SSL encrypted. Unless someone is performing a man in the middle attack and has hijacked your SSL-VPN appliance and its private encryption key, this warning can typically be safely ignored. If you are using the default self-signed certificate, this error will appear every time a web browser connects to the SSL-VPN appliance. This security mechanism is intended to ensure end-to-end security, but often confuses people into thinking something is broken. Web browsers are programmed to issue a warning if the above conditions are not met precisely.