最近我将angualr更新到了版本7。但是，当我想运行ng服务时，收到以下错误消息：
Schema validation failed with the following errors:
Data path "" should NOT have additional properties(project).
Error: Schema validation failed with the following errors:
Data path "" should NOT have additional properties(project).
at MergeMapSubscriber._registry.compile.pipe.operators_1.concatMap.validatorResult [as project] (.../node_modules/@angular-devkit/core/src/workspace/workspace.js:215:42)
at MergeMapSubscriber._tryNext (.../node_modules/rxjs/internal/operators/mergeMap.js:69:27)
at MergeMapSubscriber._next (.../node_modules/rxjs/internal/operators/mergeMap.js:59:18)
at MergeMapSubscriber.Subscriber.next (.../node_modules/rxjs/internal/Subscriber.js:67:18)
at MergeMapSubscriber.notifyNext (.../node_modules/rxjs/internal/operators/mergeMap.js:92:26)
at InnerSubscriber._next (.../node_modules/rxjs/internal/InnerSubscriber.js:28:21)
at InnerSubscriber.Subscriber.next (.../node_modules/rxjs/internal/Subscriber.js:67:18)
at MapSubscriber._next (.../node_modules/rxjs/internal/operators/map.js:55:26)
at MapSubscriber.Subscriber.next (.../node_modules/rxjs/internal/Subscriber.js:67:18)
at SwitchMapSubscriber.notifyNext (.../node_modules/rxjs/internal/operators/switchMap.js:86:26)
如何解决此问题？