typescript - Angular 4 error with angular core change detection differs after upgrade from 2 -

i have ng2 website upgraded ng4. on building, error

error in /home/docker/urlmgr-client/node_modules/@angular/core/src/change_detection/differs/iterable_differs.d.ts 

(15,48): error ts2304: cannot find name 'iterable'.

it error , never got error in ng2.

i'm not sure begin debugging this. appreciated.

i had same issue, due having file left on angular 2. need delete node_modules folder , reinstall angular.

adding "export declare type ngiterable = array | iterable" unnecessary.