We are beginning a transition of the domain name the API calls are directed to.
secure.comodo.net - becomes - secure.trust-provider.com
and
private.comodo.net - becomes - private.trust-provider.com

NOTHING about the API calls changes - just the domain name. Send the same client cert if you're using client auth, same password and parameters. Just from 'comodo.net' to 'trust-provider.com'

We are planning to sunset the secure.comodo.net. The new URLs are already live.