Post Undefined HttpClient

Hi there, i recently upgraded from V7 to V8 using the guide provided. Prior to this i was using HttpClient for my post requests and it went along fine. After the update i get a TypeError: Cannot read property 'post' of undefined i’ve been over the code a dozen times and for the life of me i can’t seem to find what’ is wrong with it.

import { Injectable } from '@angular/core';
import { HttpClient, HttpHeaders } from '@angular/common/http';
@Injectable({
  providedIn: 'root'
})
  constructor(private httpClient: HttpClient) {}

  GetCountry(): Observable<any> {
    return this.httpClient.post(
      this.apiURL + '/country/list',
      JSON.stringify({
        api_key: this.apiKey
      }),
      this.httpOptions
    );
  }

Thanks

[bkr32]

thanks for your suggestion @maxigimenez i reverted to a commit before the v8 update, cleared npm cache cleared node modules did a npm install and then a ng update it all worked out well after that

[maxigimenez]

Try a fresh install of package.json also clearing npm cache and removing node_modules.