Error when trying to enable repositories in Redhat Satellite 6.2.11

Hi,

I needed quick help as stuck here from last one week.
My Satellite server is based on Red Hat Enterprise Linux Server release 7.4 (Maipo).
I am able to access it's Web-UI.
However when I try to enable any repositories under Content -> Red Hat Repositories, get Error as follows:

SSL_connect returned=1 errno=0 state=error: certificate verify failed

I have attached screenshot for reference.
When trying to enable from hammer CLI, getting below error:

Could not enable repository:
undefined method `default_capsule?' for nil:NilClass

Please note that certificates were generated at the time of installation and I have not used any customized certificates.

Are customized certificates mandatory for Satellite Server to function finely?

Thanks!!