Unable to run "gulp serve" for our SPFx web part "This tool requires a version of NodeJS that matches" & "ReferenceError: primordials is not defined"

I have developed an SPFx web part, and now i am trying to run gulp serve … but i am getting these errors. Now i have 2 versions of node.js :-

C:\WINDOWS\system32>nvm list

  * 16.13.0 (Currently using 64-bit executable)
    8.16.2

Here are the errors:-

Your environment has been set up for using Node.js 16.13.0 (x64) and npm.

C:\Windows\System32>nvm use 8.16.2
Now using node v8.16.2 (64-bit)

C:\Windows\System32>cd C:\spfx-MyModalPopup

C:\spfx-MyModalPopup>gulp serve
Error: Your dev environment is running NodeJS version v8.16.2 which does not meet the requirements for running this tool. This tool requires a version of NodeJS that matches >=10.13.0 <11.0.0 || >=12.13.0 <13.0.0 || >=14.15.0 <15.0.0
    at SPWebBuildRig.initialize (C:\spfx-MyModalPopup\node_modules\@microsoft\sp-build-web\lib\SPBuildRig.js:27:19)
    at Object.exports.initialize (C:\spfx-MyModalPopup\node_modules\@microsoft\sp-build-web\lib\index.js:32:17)
    at Object.<anonymous> (C:\spfx-MyModalPopup\gulpfile.js:16:7)
    at Module._compile (module.js:653:30)
    at Object.Module._extensions..js (module.js:664:10)
    at Module.load (module.js:566:32)
    at tryModuleLoad (module.js:506:12)
    at Function.Module._load (module.js:498:3)
    at Module.require (module.js:597:17)
    at require (internal/module.js:11:18)

C:\spfx-MyModalPopup>nvm list

    16.13.0
  * 8.16.2 (Currently using 64-bit executable)

C:\spfx-MyModalPopup>nvm use 16.13.0
Now using node v16.13.0 (64-bit)

C:\spfx-MyModalPopup>gulp serve
ReferenceError: primordials is not defined
    at fs.js:47:5
    at req_ (C:\spfx-MyModalPopup\node_modules\natives\index.js:143:24)
    at Object.req [as require] (C:\spfx-MyModalPopup\node_modules\natives\index.js:55:10)
    at Object.<anonymous> (C:\spfx-MyModalPopup\node_modules\vinyl-fs\node_modules\graceful-fs\fs.js:1:37)
    at Module._compile (node:internal/modules/cjs/loader:1101:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1153:10)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)
    at Module.require (node:internal/modules/cjs/loader:1005:19)
    at require (node:internal/modules/cjs/helpers:102:18)

any advice why i am unable to run gulp serve to run my SPFx web part? Thanks

here are the node.js & gulp versions i have:-

C:\spfx-MyModalPopup>gulp --version
CLI version: 2.3.0
Local version: 3.9.1


C:\spfx-MyModalPopup>node --version
v16.13.0

Since you have two versions installed you can try resetting the shell after setting the version. If that does not work, set the absolute path or check your path variable.