vCenter Machine SSL certificate has expired and the upgrade will not be able to proceed until that issue is resolved.
The Fixcerts script referenced in the error has been deprecated as per Replace certificates on vCenter server using the Fixcerts script.
At this time recommending to instead use the vCert python script to manage vCenter certificates: vCert - Scripted vCenter expired certificate replacement.
Once the certificate has been replaced run the Pre-Check again to confirm the errors have cleared.