Error: Cannot find module 'symbol-observable' in Ionic 4

Question

Tried running ng serve this error keep appearing

Error: Cannot find module 'symbol-observable'
at Function.Module._resolveFilename (internal/modules/cjs/loader.js:636:15)
at Function.Module._load (internal/modules/cjs/loader.js:562:25)
at Module.require (internal/modules/cjs/loader.js:690:17)
at require (internal/modules/cjs/helpers.js:25:18)
at Object.<anonymous> (C:\Users\USER\AppData\Roaming\npm\node_modules\@angular\cli\lib\init.js:10:1)
at Module._compile (internal/modules/cjs/loader.js:776:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:787:10)
at Module.load (internal/modules/cjs/loader.js:653:32)
at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
at Function.Module._load (internal/modules/cjs/loader.js:585:3)

Answer 1

using npm

npm install --save symbol-observable

https://github.com/benlesh/symbol-observable

then import it where you using

import Symbol_observable from 'symbol-observable';