This extension contains the new user interface for the KNIME Analytics Platform. To use it, just click “Open KNIME Modern UI” in the top right corner of the KNIME Analytics Platform.
Workflow elements such as connectors or annotations are visualized in a new way and may therefore not look exactly like in the current KNIME Analytics Platform.
Extension 
KNIME Modern UI
Legal
The KNIME Remote Workflow Editor for executor is a copyrighted work owned by
KNIME AG, Zurich, Switzerland ("KNIME"), or a third party.
All rights reserved.
Update site information
KNIME Analytics Platform 5.1 Update Site, Version
5.1.0
https://update.knime.com/analytics-platform/5.1
In case you can’t install the extension via drag & drop, please check that the update site is activated .