yum returns certificate verify failed after capsule-remove on Red Hat Satellite Capsule 6.1

Issue

• After successfully running capsule-remove, yum and subscription-manager commands fail to work.
  It looks like the server is no longer registered with the Satellite.

[root@sat6 ~]# yum install capsule-installer
Loaded plugins: product-id, subscription-manager
certificate verify failed
Repo rhel-7-server-rpms forced skip_if_unavailable=True due to: /etc/rhsm/ca/katello-server-ca.pem
Repo rhel-7-server-satellite-capsule-6.1-rpms forced skip_if_unavailable=True due to: /etc/rhsm/ca/katello-server-ca.pem
https://sat6.example.com/pulp/repos/ORGANIZATION/Library/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.
https://sat6.example.com/pulp/repos/ORGANIZATION/Library/content/dist/rhel/server/7/7Server/x86_64/sat-capsule/6.1/os/repodata/repomd.xml: [Errno 14] curl#77 - "Problem with the SSL CA cert (path? access rights?)"
Trying other mirror.
No package capsule-installer available.
Error: Nothing to do
[root@sat6 ~]#
[root@sat6 ~]# subscription-manager list --available --all
Unable to verify server's identity: certificate verify failed
[root@sat6 ~]# subscription-manager register --org="ORGANIZATION" --activationkey="Activation Key"
This system is already registered. Use --force to override
[root@boi-rhsat6 ~]# subscription-manager register --org="ORGANIZATION" --activationkey="Activation Key" --force
Unable to verify server's identity: certificate verify failed
[root@sat6 ~]#