ERR_CONNECTION_REFUSED when trying to run local spfx workbench

Question

Hi all,

When I run gulp serve, on chrome it does not load the local workbench.
I get ERR_CONNECTION_REFUSED

I am able to go to https://localhost:4321/ and see all the directories
It is the same behaviour in all other browsers.
I have chrome version:86.0.4240.75 (Official Build) (64-bit)

I have Node v10.22.1
My npm is v6.14.6
My gulp is , 3.9.1
sharepoint generator is 1.11.1
I use Windows 10
I have run gulp trust-dev-cert
I have not run npm audit fix
I don't have postgress sql installed which usually blocks port 5432
I have tried unistalling all (gulp,yeoman, node,..) and reinstalling
I have disabled my antivirus and tried
I don't have any extensions in my chrome browser
In my temp folder, I don't see workbench.html created

Basically I have tried to create a webpart for sharepoint online and then run gulp serve
Below is my gulp serve output

Build target: DEBUG
[15:45:43] Using gulpfile H:\GitCentralRepo\central\spfx1\gulpfile.js
[15:45:43] Starting gulp
[15:45:43] Starting 'serve'...
[15:45:43] Starting subtask 'configure-sp-build-rig'...
[15:45:43] Finished subtask 'configure-sp-build-rig' after 6.44 ms
[15:45:43] Starting subtask 'spfx-serve'...
[15:45:43] [spfx-serve] To load your scripts, use this query string: ?debug=true&noredir=true&debugManifestsFile=https://localhost:4321/temp/manifests.js
[15:45:43] Starting server...
Starting api server on port 5432.
Registring api: /workbench
Registring api: /
[15:45:44] Finished subtask 'spfx-serve' after 435 ms
[15:45:44] Starting subtask 'pre-copy'...
[15:45:44] Finished subtask 'pre-copy' after 15 ms
[15:45:44] Starting subtask 'copy-static-assets'...
[15:45:44] Starting subtask 'sass'...
[15:45:44] Server started https://localhost:4321
[15:45:44] LiveReload started on port 35729
[15:45:44] Running server
[15:45:44] Opening https://localhost:5432/workbench using the default OS app
[15:45:44] Finished subtask 'copy-static-assets' after 64 ms
[15:45:44] Finished subtask 'sass' after 312 ms
[15:45:44] Starting subtask 'tslint'...
[15:45:45] [tslint] tslint version: 5.12.1
[15:45:45] Starting subtask 'tsc'...
[15:45:45] [tsc] typescript version: 3.3.4000
[15:45:48] Finished subtask 'tsc' after 3.38 s
[15:45:49] Finished subtask 'tslint' after 4.9 s
[15:45:49] Starting subtask 'post-copy'...
[15:45:49] Finished subtask 'post-copy' after 1.27 ms
[15:45:49] Starting subtask 'collectLocalizedResources'...
[15:45:49] Finished subtask 'collectLocalizedResources' after 4.43 ms
[15:45:49] Starting subtask 'configure-webpack'...
[15:45:50] Finished subtask 'configure-webpack' after 757 ms
[15:45:50] Starting subtask 'webpack'...
[15:45:51] Finished subtask 'webpack' after 1.52 s
[15:45:51] Starting subtask 'configure-webpack-external-bundling'...
[15:45:51] Finished subtask 'configure-webpack-external-bundling' after 1.98 ms
[15:45:51] Starting subtask 'copy-assets'...
[15:45:51] Finished subtask 'copy-assets' after 20 ms
[15:45:51] Starting subtask 'write-manifests'...
[15:45:52] Finished subtask 'write-manifests' after 1.06 s
[15:45:52] Starting subtask 'reload'...
[15:45:52] Finished subtask 'reload' after 2.08 ms

This my serve.json

{
"$schema": "https://developer.microsoft.com/json-schemas/core-build/serve.schema.json",
"port": 4321,
"https": true,
"initialPage": "https://localhost:5432/workbench",
"api": {
"port": 5432,
"entryPath": "node_modules/@microsoft/sp-webpart-workbench/lib/api/"
}
}

Please help

Answer 1

Try to change the default port(must be an unoccupied port):

{  
      "$schema": "https://developer.microsoft.com/json-schemas/core-build/serve.schema.json",  
      "port": 4321,  
      "https": true,  
      "initialPage": "https://localhost:8080/workbench",  
      "api": {  
        "port": 8080,  
        "entryPath": "node_modules/@microsoft/sp-webpart-workbench/lib/api/"  
      }  
    }  

The workbeach.html will be automatically generated after the gulp serve command runs successfully.

You can run this command netstat -ano to check the port occupancy.

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Answer 2

I tried 8080, but no luck.

netstat also did not yield anything

Please help

Answer 3

This issue is now fixed. It was caused by latest version the internet security (Kaspersky 21.1.15.500).

I went to Settings->Additional->Network
I selected Monitor selected ports only
The I clicked on "Select" next to it and unchecked "Monitor all network ports for applications that are vulnerable to network attacks