title: Angular compilation warning: "export 'ɵɵdefineInjectable' was not found in '@angular/core'
body: <p>I'm trying to serve an Angular application, but i'm getting this dependency error from "ngx-mqtt": "^6.6.0". My local CLI is 6.2.9 version. I'm trying to change versions of this dependency, but i'm still getting this error. I just can't figure out why this is happening.</p>
  
  <blockquote>
    <p>WARNING in ./node_modules/ngx-mqtt/src/mqtt.service.js 390:34-55 
    "export 'ɵɵdefineInjectable' (imported as 'i0') was not found in '@angular/core'</p>
    
    <p>WARNING in ./node_modules/ngx-mqtt/src/mqtt.service.js 390:126-137
    "export 'ɵɵinject' (imported as 'i0') was not found in '@angular/core'</p>
    
    <p>WARNING in ./node_modules/ngx-mqtt/src/mqtt.service.js 390:161-172
    "export 'ɵɵinject' (imported as 'i0') was not found in '@angular/core'</p>
  </blockquote>
  
  <p>these are my main dependencies from package.json</p>
  
  <pre><code> "dependencies": {
          "@angular/animations": "^6.1.7",
          "@angular/cdk": "^6.4.7",
          "@angular/cli": "~6.2.1",
          "@angular/common": "^6.1.0",
          "@angular/compiler": "^6.1.0",
          "@angular/compiler-cli": "^6.1.0",
          "@angular/core": "^6.1.0",
          "@angular/flex-layout": "^6.0.0-beta.18",
          "@angular/forms": "^6.1.0",
          "@angular/http": "^6.1.0",
          "@angular/material": "^6.4.7",
          "@angular/material-moment-adapter": "^6.4.7",
          "@angular/platform-browser": "^6.1.0",
          "@angular/platform-browser-dynamic": "^6.1.0",
          "@angular/router": "^6.1.0",
          "@fortawesome/angular-fontawesome": "^0.3.0",
          "@fortawesome/fontawesome-svg-core": "^1.2.21",
          "@fortawesome/free-regular-svg-icons": "^5.10.1",
          "@fortawesome/free-solid-svg-icons": "^5.10.1",
  ...
  </code></pre>
  
  <pre><code>"devDependencies": {
          "@angular-devkit/build-angular": "~0.8.0",
          "@angular/language-service": "^6.1.0",
          "@types/core-js": "^2.5.0",
          "@types/node": "~8.9.4",
          "codelyzer": "~4.3.0",
          "ts-node": "^7.0.1",
          "tslint": "^5.11.0",
          "typescript": "^2.9.2"
  }
  </code></pre>