Integration problem in Angular 6

[tanmoycsit]

When i install it using npm and try to run this project. an Error is displaying.

ERROR in node_modules/@angular/core/src/render3/ng_dev_mode.d.ts(9,11): error TS2451: Cannot redeclare block-scoped variable 'ngDevMode'.
node_modules/angular-io-overlay/node_modules/@angular/core/src/render3/ng_dev_mode.d.ts(9,11): error TS2451: Cannot redeclare block-scoped variable 'ngDevMode'.

My environment config is

Angular CLI: 6.0.8
Node: 8.11.1
OS: win32 x64
Angular:
...

Package Version

@angular-devkit/architect 0.6.8
@angular-devkit/core 0.6.8
@angular-devkit/schematics 0.6.8
@schematics/angular 0.6.8
@schematics/update 0.6.8
rxjs 6.2.2
typescript 2.7.2