The compatibility states that KNIME Big Data Connectors are certified by Cloudera for CDH 5.x, by Hortonworks for HDP 2.1 to 2.4 but should be valid also for later versions as well as MapR for MapR 4.1. with Hive 0.13.
It seems you are trying to access Knime UI withing HDP, that is not possible, the essence is to connect and work with the data. So the most appropriate access required is to the DWH over HDFS which in your case is Hive.
Question How are you trying to connect to Knime? You should use JDBC check Big Data Extensions can be purchased at http://www.knime.org/knime-big-data-extensions.
Hope that helps