Well, the error message is telling you what you nee to do. vCenter 6.7 cannot accept that SHA-1 certificate and it's asking if you want to generate a new one from the VMCA. Click yes to do so. Click no to replace the certificate manually.
You just have to click yes so that host's certificate it will be replaced. After that all is good.
The certificate store of vCenter Server cannot verify the certificate.
The SHA1 thumbprint of the certificate is:
Click Yes to replace the host's certificate with a new certificate signed by the VMware Certificate Server and proceed with the workflow.
Click No to cancel connecting to the host.
Can we give me some advice ? is very import that i finish migration before Monday.