Error is: "Failed to upgrade cluster: The Cloudera Data Science Workbench service cannot be upgraded: the target version does not support the Cloudera Data Science Workbench service type. You might need to install a newer CSD that supports the target version, or remove this service."
@pra_big Thanks for posting on Cloudera community.
The error indicating that the CSD is not compatible with the new CDSW version (CDSW1.6) as you have CSD compatible for CDH 5.14.
You need to remove old CDS file compatible to CDH5 and then download the new CSD for CDH6 from this document. Also please follow the doc to configure the CSD locations and then proceed with upgrade procedure.