Erro ao executar ng serve

polyfills.ts

import "classlist.js";

import "./node_modules/core-js/es6/array";

import "core-js/es6/date";

import "core-js/es6/function";

import "core-js/es6/map";

import "core-js/es6/math";

import "core-js/es6/number";

import "core-js/es6/object";

import "core-js/es6/parse-float";

import "core-js/es6/parse-int";

import "core-js/es6/reflect";

import "core-js/es6/regexp";

import "core-js/es6/set";

import "core-js/es6/string";

import "core-js/es6/symbol";

import "core-js/es7/reflect";

import "web-animations-js";

import "zone.js/dist/zone";

erro

./src/polyfills.ts - Error: Module build failed (from ./node_modules/@ngtools/webpack/src/ivy/index.js):
TypeError: The 'compilation' argument must be an instance of Compilation
    at getCompilationHooks (C:\sistemas\angular\Kcms.Erp.Web\node_modules\webpack\lib\javascript\JavascriptModulesPlugin.js:125:10)
    at C:\sistemas\angular\Kcms.Erp.Web\node_modules\webpack\lib\javascript\CommonJsChunkFormatPlugin.js:43:19
    at Hook.eval [as call] (eval at create (C:\sistemas\angular\Kcms.Erp.Web\node_modules\tapable\lib\HookCodeFactory.js:19:10), <anonymous>:5:1) 
    at Hook.CALL_DELEGATE [as _call] (C:\sistemas\angular\Kcms.Erp.Web\node_modules\tapable\lib\Hook.js:14:14)
    at Compiler.newCompilation (C:\sistemas\angular\Kcms.Erp.Web\node_modules\@angular-devkit\build-angular\node_modules\webpack\lib\Compiler.js:1030:30)
    at C:\sistemas\angular\Kcms.Erp.Web\node_modules\@angular-devkit\build-angular\node_modules\webpack\lib\Compiler.js:1073:29
    at Hook.eval [as callAsync] (eval at create (C:\sistemas\angular\Kcms.Erp.Web\node_modules\tapable\lib\HookCodeFactory.js:33:10), <anonymous>:13:1)
    at Hook.CALL_ASYNC_DELEGATE [as _callAsync] (C:\sistemas\angular\Kcms.Erp.Web\node_modules\tapable\lib\Hook.js:18:14)
    at Compiler.compile (C:\sistemas\angular\Kcms.Erp.Web\node_modules\@angular-devkit\build-angular\node_modules\webpack\lib\Compiler.js:1068:28)    at Compiler.runAsChild (C:\sistemas\angular\Kcms.Erp.Web\node_modules\@angular-devkit\build-angular\node_modules\webpack\lib\Compiler.js:520:8)

O que pode ser ?