SonarQube ERROR: Caused by: Failed to connect to localhost/127.0.0.1:9000

ERROR: Error during SonarQube Scanner execution
ERROR: Unable to execute SonarQube
ERROR: Caused by: Fail to get bootstrap index from server
ERROR: Caused by: Failed to connect to localhost/127.0.0.1:9000
ERROR: Caused by: Connection refused (Connection refused)