Error "Unable to register agent against Predictive Security Cloud" when installing agent

Products

• Carbon Black Cloud Endpoint Standard (formerly Cb Defense)

Issue/Introduction

While installing the Carbon Black Cloud (CBC) agent, the following error is seen:

Unable to register agent against Predictive Security Cloud.
An error occurred during registration (failed to register agent against Predictive Security Cloud).

Environment

• Carbon Black Linux Sensor: 2.6.0 and Higher
• Linux: All Supported Versions

Cause

This is most likely cause by the server, not being able to communicate with the CBC backend.

Resolution

Refer to KB: How to test connectivity using OS's built in cURL?