Did you try it with Angular 5? Still getting the same error. We are not doing anything extremely fancy, we have a component that will generate the autocomplete:

import { Component, Input, OnInit } from "@angular/core";
import { ItemsService } from "@services/items/items.service";
import { CompleterService, CompleterData } from 'ng2-completer'

@Component({
  selector: 'items-autocomplete-component',
  templateUrl: './items.autocomplete.html'
})

export class ItemsAutocompleteComponent implements OnInit {

  dataService: CompleterData;
  searchStr: string;
  allItems;
  items;

  constructor(
    private itemsService: ItemsService,
    private completerService: CompleterService
  ) { }

  ngOnInit() {
    this.itemsService.getItems().subscribe(items => {
      this.dataService = this.completerService.local(items, 'display_name', 'display_name');
    });
  }
}

and in the template:

<mdb-completer
  [label]="'items.headers.name' | translate"
  [(ngModel)]="searchStr"
  [datasource]="dataService"
  [minSearchLength]="2"
  mdbInputValidate>
</mdb-completer>