The UiPath supprt gave me the solution to resolve this issue.
During upgrade the installer will refer to the registry for the certificate subject and then it would look for the same subject in Certificates\Local Computer\Personal Store . The registry path HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\UiPath\UiPath Orchestrator\CertificateSubject
The registry values are generated during installation, if the value is changed or the certificate is changed\removed than the one used in binding now for the website, it will lead to the error above.
Ensure the value of the certificate subject is the same as the one in use for the website. Follow the below steps to check the subject name :-
Go to IIS -> Sites -> UiPath Orchestrator -> On the right hand side -> Click on “Bindings” -> SSL Certificate will give the name of the certificate in use.
Go to IIS -> Click on “Hostname” (first item in the IIS hierarchy" ) -> In the feature View Section -> Double click on “Server Certificates” -> Double click on the certificate which was found in step 1 -> Go to “Details” tab -> Look for the parameter value “Subject”
Value found in step 2 above should be the same as the registry value " CertificateSubjec t"