This error keep showing

Error: Uncaught (in promise): TypeError: Object(…) is not a function
TypeError: Object(…) is not a function
at http://localhost:8100/build/vendor.js:62751:67
at t.invoke (http://localhost:8100/build/polyfills.js:3:14976)
at r.run (http://localhost:8100/build/polyfills.js:3:10143)
at NgZone.runOutsideAngular (http://localhost:8100/build/vendor.js:5393:69)
at new AngularFirestore (http://localhost:8100/build/vendor.js:62749:41)
at _createClass (http://localhost:8100/build/vendor.js:11628:20)
at createProviderInstance$1 (http://localhost:8100/build/vendor.js:11592:26)
at resolveNgModuleDep (http://localhost:8100/build/vendor.js:11577:17)
at NgModuleRef
.get (http://localhost:8100/build/vendor.js:12814:16)
at resolveDep (http://localhost:8100/build/vendor.js:13304:45)
at c (http://localhost:8100/build/polyfills.js:3:19752)
at c (http://localhost:8100/build/polyfills.js:3:19461)
at http://localhost:8100/build/polyfills.js:3:20233
at t.invokeTask (http://localhost:8100/build/polyfills.js:3:15660)
at Object.onInvokeTask (http://localhost:8100/build/vendor.js:5436:33)
at t.invokeTask (http://localhost:8100/build/polyfills.js:3:15581)
at r.runTask (http://localhost:8100/build/polyfills.js:3:10834)
at o (http://localhost:8100/build/polyfills.js:3:7894)
at e.invokeTask [as invoke] (http://localhost:8100/build/polyfills.js:3:16823)
at p (http://localhost:8100/build/polyfills.js:2:27648)

=======================================

@ionic/cli-utils  : 1.19.2
ionic (Ionic CLI) : 3.20.0

global packages:

cordova (Cordova CLI) : 8.0.0

local packages:

@ionic/app-scripts : 3.1.9
Cordova Platforms  : none
Ionic Framework    : ionic-angular 3.9.2

System:

Android SDK Tools : 26.1.1
Node              : v8.9.4
npm               : 5.8.0
OS                : Windows 10

Search in your project for Object( and check if it finds any. Then try to see if something is wrong with your syntax

nothings wrong with the syntax, it says something about ngzone wich i never encounter before

Well, You’ll have to locate where in the code the error is coming from and your current error log isn’t providing much details, so the easiest way is to tear down your code.
Just comment some suspicious parts of the code and see at what point the error “disappears”. Then you can “move on”…