I can find no better place in this forum to post this, so I’ll just post it here.
Your HTTPS certificate is not valid or not trusted and needs to be renewed. This is not a curtesy. As a result of this, your website is completely broken to anyone who doesn’t explicitly choose to engage with it in a non-trusted fashion. It is becoming exceedingly common for people to run self-protecting extensions such as the EFF’s HTTPS Everywhere which ensure connections to websites are encrypted like they should be.
Please ensure your certificates are not illegal. It makes you look very unprofessional.