In order for RPC over HTTP to work you must have a Trusted CA Root Certificate installed and configured. This video describes a situation where you are using a self-signed certificate you will need to install the certificate into the Trusted Root Certification Authorities store.
How to unassign services from an expired key and assign them to a valid key in 9.1.0 and 9.5.1
How to automate the repository and domain back up process for disaster recovery in PowerCenter
How to find in which host the Repository Integration service is running in a multi node domain