Its very odd. This is running on an standalone EC2 instance, with no yarn. I fired a curl to the URL\n`curl -v -X POST "<http://localhost:8088/ws/v1/cluster/apps/new-application>"`\n\nAnd got the following:\n```curl -v -X POST "<http://localhost:8088/ws/v1/cluster/apps/new-application>"\n*   Trying 127.0.0.1...\n* TCP_NODELAY set\n* Connected to localhost (127.0.0.1) port 8088 (#0)\n&gt; POST /ws/v1/cluster/apps/new-application HTTP/1.1\n&gt; Host: localhost:8088\n&gt; User-Agent: curl/7.58.0\n&gt; Accept: */*\n&gt; \n* HTTP 1.0, assume close after body\n&lt; HTTP/1.0 404 NOT FOUND\n&lt; Content-Type: text/html; charset=utf-8\n&lt; Content-Length: 232\n&lt; Server: Werkzeug/1.0.1 Python/3.6.9\n&lt; Date: Sat, 26 Sep 2020 06:30:25 GMT\n&lt; \n<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">\n&lt;title&gt;404 Not Found&lt;/title&gt;\n&lt;h1&gt;Not Found&lt;/h1&gt;\n&lt;p&gt;The requested URL was not found on the server. If you entered the URL manually please check your spelling and try again.&lt;/p&gt;\n* Closing connection 0```\nWhat I don't understand is why is Superset trying to hit this URL. The 404 error is from the superset log.\n\n<http://pypi.org|pypi.org> says:\n<https://www.palletsprojects.com/p/flask/|Flask>\u00a0wraps Werkzeug, using it to handle the details of WSGI while providing more structure and patterns for defining powerful applications.