Cannot determine the module for class X in X.ts! Add X to the NgModule to fix it error in ionic2

Question

I am facing an issue when I try to build my app using the following command :

ionic cordova run android --prod --release

Everything runs fine if

Answer 1

elaborating on answer by @[Thom Kiesewetter]

It could also be a path casing issue reference used in the module or in routes or anywhere else

e.g path was

import { EmployeeComponent } from "./Entities/employee.component";

instead of

import { EmployeeComponent } from "./entities/employee.component";

where the real path was "entities" and not "Entities"