Error in Angular 6 project - An implementation cannot be declared inambient contexts

My project run build well yester day. But now when I start project, it throw an error:

ERROR in node_modules/rxjs/internal/Observable.d.ts(14,26): error TS1183: An implementation cannot be declared inambient contexts.

I have removed and reinstall @angular/cli, but cannot fix this issue.
Angular CLI: 6.0.8
Node: 9.11.1
rxjs 6.2.1
typescript 2.7.2
webpack 4.8.3