Error during LiteSpeed v9 Installation - certificate chain

At the Activity logging portion of the Litespeed install, the Litespeed install fails with:

"SSL Provider: The certificate chain was issued by an authority that is not trusted"

 The Windows Event Log shows:

The certificate received from the remote server was issued by an untrusted certificate authority. Because of this, none of the data contained in the certificate can be validated. The TLS connection request has failed. The attached data contains the server certificate.

 The SSPI client process is SLSInstaller (PID: 9096).

I've installed many times on other servers with no issues.  Any ideas?