problems posting on website

I am receiving this message: Duck Duck Go can't load this page. The certficate for this server is invalid. You might be connecting to a server that is pretending to be "hstrial-sharris648.homestead.com" which could put your confidential information at risk.

What is going on? I tried to do this post in Duck Duck Go and also in Firefox.

Firefox says: Warning: Potential Security Risk Ahead

Firefox detected an issue and did not continue to hstial-sharris648-hoemstead.com. The website is either misconfigured or your comptuer clock is set to the wrong time. It's lidely the website's certificate is expired, which prevents Firefox from connecting securely. If you visit this site attachers could try tot steal information like your passwords, emails or credit card details. 

It later says to notify you. 

Help! Please!