Uncaught Error: Cannot find module './scroll-view' - ionic4

Question

im having a problem at run time only when build with --prod flag
im using vscode with
Ionic:
Ionic CLI : 5.2.5
(C:\Users\elile\AppData\Roaming\npm\node_modules\ionic)
Ionic Framework : #ionic/angular 4.3.1
#angular-devkit/build-angular : 0.13.8
#angular-devkit/schematics : 7.3.8
#angular/cli : 7.3.9
#ionic/angular-toolkit : 1.5.1
Cordova:
Cordova CLI : not installed
Cordova Platforms : not available
Cordova Plugins : cordova-plugin-ionic-keyboard 2.1.3, cordova-plugin-ionic-webview 4.1.1, (and 9 other plugins)
Utility:
cordova-res : 0.6.0
native-run : 0.2.8
System:
Android SDK Tools : 26.1.1 (D:\android\sdk)
NodeJS : v10.15.3 (C:\Program Files\nodejs\node.exe)
npm : 6.4.1
OS : Windows 10

Answer 1

Somewhere you have used Scroll View module but not put it into the parent modules declarations.
Check every place that you have used Scroll View and see if the module is defined in that parent module.
update
if its an issue with the packages then I would generate a new app and then either copy the package versions back to your current broken app, or just migrate the app into the new app.

Answer 2

The plugin breaks with ionic 4, ionic-angular became #ionic/angular.
If you have used "ionic-angular" library for import then changed for ionic 4
Change "ionic-angular" to "#ionic/angular"
Like that : import { Events } from '#ionic/angular';