me sale este error Error: Template parse errors: ‘router-outlet’ is not a known element: <ol> <li>If ‘router-outlet’ is an Angular compon...

me sale este error

Error: Template parse errors:

‘router-outlet’ is not a known element:

1. If ‘router-outlet’ is an Angular component, then verify that it is part of this module.
2. If ‘router-outlet’ is a Web Component then add ‘CUSTOM_ELEMENTS_SCHEMA’ to the ‘@NgModule.schemas’ of this component to suppress this message. ("

–>

[ERROR ->]<router-outlet>

</router-outlet>"): ng:///AppModule/AppComponent.html@62:0

compiler.js:215

que debo hacer? 😕