该问题可能出现在使用 APP_INITIALIZER 时，由于异步加载数据的原因，导致该方法无法正确地监测到数据变化，从而报错。解决方法是在 APP_INITIALIZER 中使用 Promise 将数据加载过程转换为同步方式，确保数据已经加载完毕后再执行相应操作。代码示例如下：

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';

@Injectable()
export class DataService {

  public data: any;

  constructor(private http: HttpClient) {}

  loadData() {
    return this.http.get('url')
      .toPromise()
      .then(data => {
        this.data = data;
      });
  }
}

export function dataInitializer(dataService: DataService) {
  return () => dataService.loadData();
}

在 AppModule 中配置：

import { NgModule, APP_INITIALIZER } from '@angular/core';
import { HttpClientModule } from '@angular/common/http';
import { DataService, dataInitializer } from './data.service';

@NgModule({
  imports: [
    HttpClientModule
  ],
  providers: [
    DataService,
    {
      provide: APP_INITIALIZER,
      useFactory: dataInitializer,
      deps: [DataService],
      multi: true
    }
  ]
})
export class AppModule {}

在组件中使用：

export class ExampleComponent implements OnInit {

  constructor(private dataService: DataService) {}

  ngOnInit() {
    this.dataService.loadData().then(() => {
      console.log(this.dataService.data);
    });
  }
}