'Why my node returns me a websocket error?

I'm putting my application on an IIS HTTP server, but I get an error:

WebSocket connection to 'wss://xxxx.xxxx.xx:xxxxx/?designer=1&token=&baa=' failed: Error during WebSocket handshake: net::ERR_CONNECTION_RESET.

What could cause it?

dataflow total.js

Solution 1:^[1]

This issue might occur if 'PORT' is closed. To resolve this issue make sure that PORT is open.

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Solution	Source
Solution 1	Bhargav Rao