custom module - directive not found

I\\\'m trying to use any directive from  module (not the app.module) and I always got an error that the directive is not found.This is a sample module import { BrowserModule } from \\\'@angular/platform-browser\\\'; import { BrowserAnimationsModule } from \\\'@angular/platform-browser/animations\\\'; import { NgModule } from \\\'@angular/core\\\'; import { TeComponent } from \\\'./te.component\\\'; import { MDBBootstrapModule } from \\\'../../typescripts/free\\\'; @NgModule({ declarations: [TeComponent], imports: [ BrowserModule, BrowserAnimationsModule, MDBBootstrapModule ] }) export class TeModule { } and a sample component <button class=\\\"btn btn-primary waves-light\\\" type=\\\"button\\\" (click)=\\\"test1.toggle()\\\" mdbRippleRadius> Toggle collapse </button> <mdbCollapse #test1> <p>Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident.</p> </mdbCollapse> if i move the code from the custom component to the app component it works fine. but the app is modular and has a lot of custom modules.

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