Ng build --prod fails

When I run ng build or ng serve everything goes well but ng build --prod just goes bad
Some output

src/app/das orhboard/cotizaciones/add/ - error NG8001: 'ion-column' is not a known element:
1. If 'ion-column' is an Angular component, then verify that it is part of this module.
'@NgModule.schemas' of this component to suppress this message.
179         <ion-column>

    22   templateUrl: './',
    Error occurs in the template of component AddPage.

[ERROR] An error occurred while running subprocess ng.