has no exported member 'Observable'. code example

Example 1: rxjs/Observable"' has no exported member 'Observable'

It looks like rxjs-compat is missing. 
just do 
> npm i rxjs-compat 
right after 
> npm install 
then do 
> ng serve -o

Example 2: has no exported member 'AppComponent'

export class YourModelComponent {
   ...
}
   
   
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