yum - Problem with the SSL CA cert

Hello,

My RHEL (was 7.2, now 7.4) system is registered with RedHat, but when I run yum I get:

$ sudo yum -y update
Loaded plugins: langpacks, product-id, rhnplugin, search-disabled-repos, subscription-manager
This system is not registered with RHN Classic or Red Hat Satellite.
You can use rhn_register to register.
Red Hat Satellite or RHN Classic support will be disabled.
Repo rhel-7-server-rpms forced skip_if_unavailable=True due to: /etc/rhsm/ca/katello-server-ca.pem
https://cdn.redhat.com/content/dist/rhel/server/7/7Server/x86_64/os/repodata/repomd.xml: [Errno 14] curl#77 - "Problem with the SSL CA cert (path? access rights?)"
Trying other mirror.
No packages marked for update

Running $ sudo yum reinstall ca-certificates was encouraging, but did not improve my issue above...

Editing /etc/yum.repos.d/redhat.repo and setting sslverify = 0 for the [rhel-7-server-rpms], which is the only one enabled, allowed me to get yum working (I now have RHEL 7.4). But I still want to resolve this SSL CA issue!

Any help would be appreciated.

Brian