Attempts to install the BCCA (Auth Connector) fail even though the server's certificate store shows an Entrust certificate installed.

Entrust Certification Authority (2048) is a prerequisite for the installation of the Auth Connector, see document: Deploy the Auth Connector.

Confirm that the Entrust 2048 certificate is the Entrust certificate installed. There are several different versions of Entrust certs, the certificate that the installation is looking for is Entrust Certification Authority (2048).  

Download the Entrust CA (2048) root certificate from Entrust.net

Entrust site with all root certificates:

https://www.entrust.com/get-support/ssl-certificate-support/root-certificate-downloads/

Direct download link:

https://www.entrust.com/root-certificates/entrust_2048_ca.cer

Please note:

If you are planning to use an IPSEC connection method with BCCA authentication, you may also need to install the Entrust L1C Intermediate certificate if your host PC does not already trust it.

Here is the link to the page with all Entrust certificates:

https://www.entrust.com/get-support/ssl-certificate-support/root-certificate-downloads/

Direct download link:

https://www.entrust.com/root-certificates/entrust_l1c.cer