SSTP VPN is giving me errors after no changes.

I have 6 SSTP VPN connections set up on my work computer. 5 are still working, but 1 just stopped working today.I was using it all day yesterday, and no changes were made on the computer, or the router, but I started getting this message when I would try to connect to the VPN “A certificate chain processed, but terminated in a root certificate which is not trusted by the trust provider” any ideas on what may have caused this? After getting this message, I created a new certificate and installed it on my windows machine, but I still can not connect to my VPN.